Multi Tech Systems Network Card MT2834BLR User Manual

MT2834BR/MT2834BLR  
Intelligent Data/Fax  
Rack Mounted Modem  
User Guide  
 
Contents  
Chapter 1 - Introduction ................................................................ 5  
1.1 Introduction .............................................................................. 6  
1.2 Features ................................................................................... 6  
1.3 How to Use This Manual ......................................................... 7  
Chapter 2 - Installation .................................................................. 8  
2.1 Preliminaries ............................................................................ 9  
2.1.1 Card Cage .................................................................... 9  
2.1.2 Serial Cable ................................................................. 9  
2.1.3 Telephone Line ............................................................ 9  
2.2 Installation .............................................................................. 10  
2.3 PC Board Controls ................................................................. 11  
2.3.1 DIP-Switch Settings ................................................... 12  
2.4 OOS (Busy Out) Toggle Switch ............................................ 14  
2.4.1 Out of Service/Test Jumper ...................................... 15  
2.4.2 MI/MIC Option Jumper .............................................. 15  
2.5 Dial-Up and Leased Lines ..................................................... 16  
2.6 Modem LED Indicators .......................................................... 17  
Chapter 3 - Installation ................................................................ 19  
3.1 Introduction ............................................................................ 20  
3.2 Serial Port Limitations............................................................ 20  
3.2.1 How Can You Identify Your UART Type? ................ 21  
3.3 Configuring Your Software .................................................... 23  
3.3.1 ConfiguringSoftware for Your Modem ...................... 23  
3.4 PC Initialization Strings ......................................................... 24  
3.4.1 Changing Default Parameters................................... 26  
3.5 Macintosh Initialization .......................................................... 26  
3.6 Configuring Software for Your Computer ............................. 27  
3.6.1 Configuring Software for the Remote System.......... 28  
3.6.2 Terminal Emulation .................................................. 28  
3.6.3 File Transfer Protocols .............................................. 29  
3.7 When to Disable Data Compression ..................................... 29  
3.7.1 Disabling Error Correction ......................................... 30  
Chapter 4 - ModemCommands................................................... 31  
4.1 Modem AT Commands .......................................................... 32  
4.1.1 Callback Security Commands ................................... 43  
4.1.2 Remote Configuration ............................................... 45  
4.1.3 Remote Configuration Procedures ........................... 45  
4.1.4 V.25bis Commands ................................................... 46  
 
4.2 S-Registers............................................................................. 48  
4.3 Result Codes.......................................................................... 52  
4.3.1 AT Commands and S-Register Summary ................ 55  
Chapter 5 - Modem Testing ........................................................ 56  
5.1 Local Analog Loopback Test/V.54 Loop 3 ............................ 57  
5.2 Digital Loopback Test/V.54 Loop 2  
(Local/Manual) ....................................................................... 58  
5.3 Digital Loopback Test/V.54 Loop 2  
(Remote/Automatic) ............................................................... 60  
5.4 Local Analog Loopback Test  
(Synchronous Mode).............................................................. 61  
5.5 Digital Loopback Test (Local/Manual)  
(Synchronous Mode).............................................................. 62  
5.6 Digital Loopback Test (Remote/Automatic)...............................  
(Synchronous Mode).............................................................. 63  
Chapter 6 - Warranty and Service.............................................. 64  
6.1 Introduction ............................................................................ 65  
6.2 Limited Warranty .................................................................... 65  
6.3 Tech Support.......................................................................... 66  
6.3.1 Recording Modem Information.................................. 66  
6.3.2 Service ....................................................................... 66  
6.4 Upgrading the MT2834BR ..................................................... 67  
6.4.1 Using FlashPro to Upgrade Modem Firmware ......... 67  
6.5 Safety Warnings..................................................................... 68  
6.6 Internet ................................................................................... 69  
Chapter 7 - BABT Requirements................................................ 70  
7.1 Compliance with BABT Requirements .................................. 71  
7.1.1 European Low Voltage Directive .............................. 72  
7.1.2 Compliance with BS6305 Clause 6.2, BS6320  
Clause 7.2, and BABT/SITS/82/005S/D ................... 72  
7.1.3 Compliance with BS6789: Section 3.1 and Part 2 ... 73  
7.1.4 Compliance with BS6328 Part 1 ............................... 74  
Appendices ................................................................................... 75  
Appendix A ..................................................................................... 76  
FCC Regulations for Telephone Line Interconnection ........ 76  
Canadian Limitations Notice ................................................. 78  
Appendix B ..................................................................................... 79  
Technical Specifications ........................................................ 79  
Index .............................................................................................. 84  
 
Chapter 1 - Introduction  
 
Chapter 1 - Introduction  
1.1  
Introduction  
Welcome to the world of data communications. You have acquired one of  
the finest intelligent data/fax modems available today, either the model  
MT2834BR or MT2834BLR (MT2834), from Multi-Tech Systems. Your  
MT2834 modem provides data communication at 33,600-14,400 bps  
(*Enhanced V.34/V.32bis), as well as other prevalent datacomm standards.  
The MT2834 also includes adaptive protocol enhancing used in typical  
Unix® batch file transfers and support for IBM's AS/400 (iSeries)TM and  
System3xTM environment. The MT2834BLR provides support for dial back-  
up with automatic leased line restoral. This User Guide will help you install,  
configure, test and use your MT2834 data/fax modem.  
*Note enhancements on V.34 code (33.6K/31.2K) is awaiting formal ITU  
approval; the ITU study group 14 has agreed on the technical side of the  
proposal, with formal approval expected at the next ITU meeting in  
Geneva.  
1.2  
Features  
The MT2834 automatically adjusts to line conditions and the capabilities of  
the modem it connects to, resulting in the highest possible speed, the most  
accurate error correction, and the most efficient data compression possible  
for each connection. The MT2834 is designed for data rates as high as  
33,600 bps in full-duplex mode over public telephone lines.  
MT2834 features include:  
· Support of data rates of 33,600, 31,200, 28,800, 26,400, 24,000, 21,600,  
19,200, 16,800, 14,400, 12,000, 9600, 7200, 4800, 2400, 1200, 0-300  
bps.  
· Automatic fallback to slower speeds in noisy line conditions, and fall-  
forward to faster speeds as conditions improve.  
· ITU-T V.42 LAP-M and MNP Classes 3 and 4 error correction.  
· Data transfer rates up to 115,200 bps with V.42bis 4-to-1 data  
compression.  
6
 
· Automatic disabling of compression when transferring already-  
compressed files.  
· Serial port data rates adjustable to 115.2K bps.  
· Autodial, redial, pulse (rotary) and touch-tone dial.  
· Dial tone and busy signal detection for reliable call-progress detection.  
· Compatibility with the standard AT command set used by most  
communication programs.  
· On-screen help menus.  
· Nonvolatile memory for storage of customized modem parameters and  
ten telephone numbers.  
· Sends and receives faxes from your computer at 14,400, 9600, 7200 or  
4800 bps.  
· Responds to EIA TR.29 Class 2 fax commands.  
· Supports UNIX-to-UNIX® UUCP Spoofing.  
· Supports IBM's AS/400 (iSeries)TM and System3x environment.  
1.3  
How to Use This Manual  
This chapter begins with a short introduction, a profile on modem features,  
followed by a guide (which you are now reading) to the use of this manual.  
This manual includes hardware installation and configuration described in  
Chapter 2. Chapter 3 covers communication software configuration  
recommended for the MT2834. Other issues covered include setting up  
initialization strings, changing default parameters, configuring software for  
the remote system and file transfer protocols. Chapter 4 covers modem AT  
commands, Remote Configuration commands, S-Registers and Result  
Codes. Chapter 5 illustrates the MT2834 diagnostic capabilities, providing  
Analog and Digital Loopback testing procedures. Chapter 6 explains  
product warranty and technical support. Appendices A and B respectively  
describes FCC requirements and regulations and technical specifications.  
 
Chapter 2 - Installation  
 
Chapter 2 - Installation  
2.1  
Preliminaries  
This chapter covers MT2834 installation and connection. In addition to the  
contents of the MT2834 package, you will need the equipment listed  
below.  
2.1.1 Card Cage  
The MT2834 is designed to mount in the Multi-Tech Systems' modem rack  
(see Section 2.2 for various models available). This rack is an EIA-  
standard 19-inch wide by 7-inch high rack, and mounts in any standard  
computer cabinet. The rack has a sixteen modem slot capacity, one power  
supply source (the CC1600 series card cage has a redundant power  
supply capability), sixteen 25-pin (female) connectors for RS232C/V.24  
interface and sixteen DB9 (female) connectors for phone line (the CC1600  
series card cage has RJ11 back-plane connectors for phone line interface).  
2.1.2 Serial Cable  
You must provide a serial cable to connect each corresponding MT2834 to  
your computer. The cable must have a DB-25 male interface into the  
modem rack.  
2.1.3 Telephone Line  
The MT2834 uses one RJ11 jack per corresponding modem slot to  
connect to the telephone lines. To connect the modem to the phone lines,  
plug one end of the RJ11 cable that is provided with the modem into the  
DB9 (9-pin connector) located on the back plane of the modem rack and  
the other end into the phone-company-provided RJ11 or RJ11W modular  
phone jack (CC916, CC1416 or CC2816 racks). To connect the modem to  
the phone lines using the CC1600 modem rack, plug one end of the RJ11  
cable provided with the modem into the rack's RJ11 connector (located on  
the back plane of the modem rack) and the other end into the phone-  
company-provided RJ11 or RJ11W modular phone jack.  
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Chapter 2 - Installation  
2.2  
Installation  
Perform the following procedure to install modem cards in the CC916,  
CC1416, CC2816 or CC1600 racks*. The installation process involves:  
1. Power cord must be unplugged prior to installation of the Power  
Source(s). Insert Power Source(s) (PS216A or PS1600) into far right of  
the rack cage.  
2. Slide a modem card into one of sixteen available modem slots. Start by  
inserting a modem into the left-most channel (slot #1) of the rack. The  
toggle switch should be at the bottom of the card, with the component  
side of the card facing the right. The modem’s gold edge connector is  
offset so that the modem cannot be inserted incorrectly. Continue  
installing modem cards as necessary.  
3. Plug RS232C Cable into appropriate modem slot (DB25/25-pin  
connector-female) at rear of rack. Note: Any cables connected to the  
computer must be shielded to reduce interference.  
4. If you are connecting your phone line directly to the modem card, plug  
the phone line cable into the appropriate modem slot (DB9/9-pin  
connector-female) at the rear of the rack and the other end into the  
phone-company-provided RJ11 or RJ11W modular phone jack. To  
connect the modem to the phone lines using an CC1600 modem rack,  
plug one end of the RJ11 cable provided with the modem into the rack's  
RJ11 connector (located on the back plane of the modem rack) and the  
other end into the phone-company-provided RJ11 or RJ11W modular  
phone jack.  
5. Plug in modem rack power cord.  
6. Verify remote modem's current configuration settings with your  
MT2834BR in terms of data compression, error correction, transmission  
rate, etc. (ATL5/ATL7 Command - see Chapter 4 on AT commands).  
7. Attach MT2834BR to dial-up phone lines and/or leased lines and verify  
DIP-Switch #10 and #5 settings (Section 2.5).  
8. Make sure modem and computer/terminal serial port baud rates are  
adjusted (Section 2.5.).  
10  
 
Chapter 2 - Installation  
9. Set both local and remote modems to either Normal (&E0&W0) mode  
or to Reliable (&E2&W0) mode.  
10. Verify leased line transmit level (DIP-Switch #3) setting (Section 2.3.1).  
11.Proceed to Chapter 3 of this manual, or to your data communications  
software manual.  
* All Multi-Tech rack-mounted modem cards (except MT1432/2834) are  
interchangeable among all types of modem racks. There is, however, slight  
LED differences. Model #CC216G is a “generic” modem rack for any rack  
mount modem card. The user affixes LED labels on a per slot basis depending  
on modem type.  
2.3  
PC Board Controls  
The MT2834 is designed on a single printed circuit board. This board  
contains sixteen DIP-Switches. There is a two-position"Out of Service"  
(OOS) toggle switch that extends from the front of the modem circuit card.  
There is also a two-position MI/MIC berg jumper and TEST/OOS berg  
jumper.  
11  
 
Chapter 2 - Installation  
The sixteen DIP-Switches and two berg jumpers control various modem  
options or set default values for the MT2834 Command mode. There is a  
difference in how several of the switches operate depending on whether  
you are in synchronous or asynchronous mode (DIP-Switch #12).  
Most communications software packages have installation procedures of  
their own, which call for certain modem DIP-Switch settings. If you are  
using a package other than MultiExpress, follow the software's instructions.  
2.3.1 DIP-Switch Settings  
The vast majority of installations are similar, with the MT2834 being used  
to dial up a remote installation where the call is automatically answered.  
The factory default DIP-Switch settings are based on this assumption. The  
following is a brief description and summary of the MT2834's DIP-Switch  
options:  
Switch Function  
Position Effect  
#1  
#2  
#2  
#3  
#3  
#4  
#4  
#5  
DTR Forced/  
DTR from Interface *  
UP*  
DOWN  
DTR forced from  
computer/terminal  
Flow Control &E4*  
(Async/Dial-Up/Leased Line) DOWN  
UP*  
Hardware flow  
control enabled  
SDLC*/BSC (Sync)  
UP*  
DOWN  
SDLC enabled  
Result Codes Enabled*  
(Async Dial-up)  
UP  
DOWN*  
Modem responses  
are echoed  
DbM Transmit -15dB/-11dB* UP  
(Async/Sync/Leased Line)  
Lease Line  
transmits at -11dB  
DOWN*  
UUCP Disabled* (Async  
Dial-Up/Leased Line)  
UP*  
DOWN  
UUCP  
"spoofing" Disabled  
AS/400 Mode Disabled*  
(Sync Dial-Up/Leased Line)  
UP*  
DOWN  
AS/400 Mode  
Disabled  
Auto-Answer Enabled*  
Async/Sync/Dial-Up)  
UP*  
DOWN  
Auto-Answer  
in dial-up mode  
* Factory default setting.  
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Chapter 2 - Installation  
Switch Function  
Position Effect  
#5  
Answer/Originate*  
UP*  
Originate call in  
(Async/Sync/Leased Line)  
DOWN  
Lease Line mode  
#6  
Max-Throughput Enabled*  
(Async/Dial-Up/Leased)  
UP*  
DOWN  
Modem set-up to  
operate at highest  
efficiency level  
#6  
Slave Clock Disabled*  
(Sync/Dial-Up/Leased)  
UP*  
DOWN  
Clock controlled  
by remote device  
#7  
RTS/Normal/Forced*  
UP  
RTS Forced On  
(Sync/Async/Dial/Leased)  
DOWN*  
#8  
Command Mode Enabled*  
(Sync/AsyncDial/Leased)  
UP  
Command Mode  
DOWN* Enabled  
UP Remote  
DOWN* LoopBack Enabled  
#9  
Local/Remote LoopBack*  
(Async/Sync/Dial/Leased)  
#10  
#11  
#11  
#12  
Dial-Up*/Leased-Line  
UP*  
DOWN  
Dial-Up Enabled  
"AT"/Multi-Tech Result Codes UP  
(Asynchronous)  
Multi-Tech Result  
DOWN* Codes Enabled  
UP Selects Transmit  
DOWN* Clock Source  
Internal*/External Clocking  
(Synchronous)  
Sync/Async Mode*  
UP  
Async Enabled  
DOWN*  
13  
 
Chapter 2 - Installation  
Dip Switch Settings #13 - 16  
Note: A modem baud rate command (e.g., $MB33600) overrides the  
setting of the speed selection switches (#13 and #14).  
Switch Position  
Effect  
13/14 UP/UP*  
28.8 K bps Operation (Default)  
13/14 DOWN/UP  
13/14 UP/DOWN  
13/14 DOWN/DOWN  
19.2 K bps Operation  
14.4 K bps Operation  
9600 bps Operation  
#15  
#15  
UP*  
DOWN  
CD/DSR from Interface  
CD/DSR Forced On  
#16  
#16  
UP  
DOWN  
Used in combination with  
DIP-Switch #9/Loopback Tests  
* Factory default setting  
2.4  
OOS (Busy Out) Toggle Switch  
The MT2834 contains a two-position OOS switch on the front panel. This  
switch can be used to create a “busy out” (OOS) condition for the modem  
(i.e., take the modem off-hook). To place a modem in the Busy condition,  
move the OOS toggle switch to the (BUSY) position. The modem then  
goes off-hook, its OOS and OH LEDs light, and incoming calls to this  
modem get a busy signal. If you suspect a problem with a particular  
modem, you can use the BUSY switch to have an optional device (such as  
a “hunt group”) that looks for a non-busy line to perform a “roll over” to the  
next available modem while you check the status of the Busy modem.  
14  
 
Chapter 2 - Installation  
2.4.1 Out of Service/Test Jumper  
When the MT2834 is Out Of Service (OOS), it is busy to incoming calls. In  
the Test (default) setting, the modem drives pin 25 high when the modem  
is in Test mode. In the OOS (optional) setting, the computer or terminal  
forces pin 25 high and puts the modem in a busy condition. Note that  
jumper (shorting) plugs are not shipped with the MT2834, but is provided  
by Multi-Tech’s Tech Support group on request.  
Test Setting  
(Factory Default)  
OOS Setting  
(Optional)  
2.4.2 MI/MIC Option Jumper  
To activate MI/MIC option (Mode Indicate/Mode Indicate Common  
Interface), you must first move MI/MIC jumper plugs. The $MI command,  
then controls this function (AT$MI1 enables MI/MIC and AT$MI0 disables  
MI/MIC). This option is for applications where the modem's dialing  
capability is not used, and dialing is done by an external device (such as a  
801 dialer, a computer, or a PBX/CBX system dialer).  
MI/MIC  
MI/MIC  
MI/MIC Disabled  
(Factory Default)  
MI/MIC Enabled  
(Optional)  
15  
 
Chapter 2 - Installation  
2.5  
Dial-Up and Leased Lines  
Connection to the phone system is made via RJ11 type jacks such as an  
RJ11C or RJ11W. It can also be connected to an RJ41 or an RJ45S jack,  
but would not use these jack's dB-level programming features. The  
MT2834 is designed to transmit at a permissive level of -11dB.  
To connect the modem to the phone lines, plug one end of the RJ11 cable  
that is provided with the modem into the corresponding DB9 or RJ11  
connector (dependent upon card cage used) located on the back plane of  
the modem rack and the other end into the phone-company-provided RJ11  
or RJ11W modular phone jack. Make sure that DIP-Switch #10 is in the UP  
position (default) when in dial-up mode.  
Although the majority of installations involves dial-up lines, the MT2834  
also connects to two-wire leased lines (sometimes referred to as  
dedicated, private, or 3002 lines).  
To connect the modem to leased lines, first determine the type of line  
termination provided by the phone company. Most phone companies  
provide a terminal block with a pair of screws. Some provide a  
conventional RJ11 type of connector. If the RJ11 connector is used, you  
can use the same cable that you use for dial-up connection. If the screw  
terminal type connector is used, you may need to order the #CA167 cable  
from Multi-Tech Systems.  
Make two DIP-Switch setting changes on the modem's PC board. The first  
involves placing DIP-Switch #10 in the DOWN position (changes the  
modem from dial-up to leased line operation). The second DIP-Switch  
change requires that one of the two modems on the leased line circuit is  
set to "originate", and the other is set to "answer". To do this, change the  
setting of DIP-Switch #5. When you changed the DIP-Switch #10 setting,  
you also changed the function of DIP-Switch #5. Now the UP position  
selects answer mode frequencies while the DOWN position selects  
originate mode frequencies. Place DIP-Switch #5 in the UP position on  
one of the two modems, and on the other modem, place Switch #5 DOWN.  
It doesn't matter which is which, just so you have local and remote  
modems in opposite modes.  
16  
 
Chapter 2 - Installation  
2.6  
Modem LED Indicators  
The MT2834 has ten LED diagnostic indicators.  
RCV XMT CO 28.8 14.4  
24  
OH  
DTR  
RI ERR  
1. Receive Data (RCV). This LED blinks when data is being received, on  
for a space, off for a mark. The state of this RCV LED matches that of  
the RCV circuit on Pin 3 of the RS232C/V.24 interface.  
2. Transmit Data (XMT). This LED blinks when data is being transmitted,  
on for a space, off for a mark. The state of this LED matches that of the  
XMT circuit on Pin 2 of the RS232C/V.24 interface.  
3. Carrier ON (CO). This LED lights when a valid carrier tone has been  
detected.  
4. 28,800 bps (28.8). This LED is lit when the modem is connected at  
28,800 bps.  
5. 14,400 bps (14.4). This LED is lit when the modem is connected at  
14,400 bps. Note that when both 28.8 and 14.4 LEDs light, modem is in  
21,600-26,400 bps mode of operation.  
6. 2400 bps (24). This LED is lit when the modem is connected at 2400  
bps.  
7. Off Hook (OH). This LED is lit when the phone line is “off hook”. This  
occurs when the modem is dialing, on line, or answering a call. The  
LED also flashes when the modem is pulse dialing in the Command  
Mode.  
8. Data Terminal Ready (DTR). When the DTR LED is lit, the modem is  
permitted to answer an incoming call. When DTR goes off, a connected  
modem disconnects if dependent on DTR. The state of this DTR LED  
matches that of the DTR circuit on Pin 20 of the RS232C/V.24 interface.  
9. Ring Indicator (RI). This LED is lit during the ringing interval as an  
incoming call is received.  
17  
 
Chapter 2 - Installation  
10. Error (ERR). When the ERR LED is flashing, the leased line is down  
and the modem is in self-test mode has failed. When ERR LED is on,  
this indicates the modem is in an out of service (OOS) state. When the  
modem is out of service, it is busy to incoming calls.  
NOTE: To verify Enhanced V.34 mode is engaged:  
1. Type +++AT<CR> .  
2. Type ATL8 .  
3. The modem's current on-line condition is displayed. An  
example of L8 listing is shown below.  
Figure 2-2. On-Line Diagnostics  
18  
 
Chapter 3 - Installation  
 
Chapter 3 - Configuration  
3.1  
Introduction  
Since your communications software configuration is affected by the  
capabilities of your computer, this chapter begins with a discussion of the  
limitations of some serial ports and how to identify them. It then discusses  
communications configuration in general and recommends settings  
specifically for the MT2834.  
3.2  
Serial Port Limitations  
When you configure your software, you need to consider how the hardware  
on both ends of the connection will affect the connection. Some serial  
ports, particularly those in older PC-compatible computers, may limit the  
performance of the MT2834. You should know if yours is one of them.  
The limiting factor is an integrated circuit called a Universal Asynchronous  
Receiver/Transmitter, or UART. All data from your modem flows through it.  
The UARTs typically used in PC-compatible computers are types 8250,  
8250A, 16450, and 16550AFN. The 8250 is unreliable above 9,600 bps,  
and the 8250A and 16450 are unreliable above 19,200 bps. If the modem  
sends data to the UARTs above those speeds, the UARTs may not be able  
to process the data fast enough to keep from losing some of it. The  
16550AFN, however, can safely handle data to 115,200 bps.  
When a modem communicates with V.42bis 4-to-1 compression enabled, it  
sends up to four times as much uncompressed data to the serial port as it  
receives compressed over the telephone line. Therefore, a modem  
communicating at 14,400 bps may require a serial port that can reliably  
transfer data at four times 14,400 bps, or 57,600 bps; at 19,200 bps it may  
require one that works reliably up to four times 19,200 bps, or 76,800 bps;  
and at 28,800 and 33,600 bps it may require one that works reliably up to  
a maximum of 115,200 bps. If your serial port cannot handle these speeds,  
we recommend that you replace your present serial card with one that has  
a 16550AFN UART or equivalent.  
Macintosh computers do not use UARTs. The Macintosh SE through IIfx  
models use a Zilog Z8530 chip called a Serial Communications Controller,  
or SCC, that has a maximum speed of 57,600 bps. This speed can be  
20  
 
Chapter 3 - Configuration  
compromised by other serial communications, including printer  
transmissions and Appletalk, the networking software that allows  
Macintoshes to share files. When Appletalk is active it controls all serial  
communications on the Macintosh. Because it gives priority to network  
communications, it may lose modem data at higher transmission speeds.  
Therefore, when Appletalk is active you risk losing data on serial port  
communications over 2400 bps, though most users can work up to 9600  
bps without problems. Other activities that could cause the serial driver to  
drop bits at high speeds include the floppy disk driver formatting a disk, the  
CPU paging in or out in virtual memory mode, and the Mac IIci or IIsi  
running the on-board video in 8-bit mode. Therefore, for maximum  
communications speed on the Macintosh, we recommend as few  
concurrent activities as possible. To use V.42bis compression at 19,200  
bps or faster, we recommend that you install a high speed serial port card.  
Newer Macintosh computers, such as the Quadra and Centris models,  
support serial port speeds up to 115,200 bps.  
3.2.1 How Can You Identify Your UART Type?  
If you have MS-DOS 6.0 or later, you can find your UART type from a  
diagnostic program called MSD. To use it, type MSD at the DOS prompt.  
After the opening screen, select COM Ports. The last line of the report tells  
you what type UART you have for each COM port. MSD does not  
distinguish between the 8250 and the 8250A. However, if you have an IBM  
AT or newer computer, you likely have an 8250A or 16450 UART installed,  
both of which are reliable to 19,200 bps. If you would like more detailed  
information about your UART than MSD can provide, you can download  
shareware UART identification programs from the IBM Communications  
Forum.  
21  
 
Chapter 3 - Configuration  
Figure 3-1. MSD UART Identification, Screen 1  
Figure 3-2. MSD UART Identification, Screen 2  
22  
 
Chapter 3 - Configuration  
3.3  
Configuring Your Software  
Communications software must be configured to work with your modem,  
your computer, and the remote system it is calling. Fortunately, most  
communications programs make the process easy by providing a default  
initialization string for your modem as well as defaults for most of the other  
required parameters.  
3.3.1 Configuring Software for Your Modem  
Because remote computers may have different connection requirements  
such as speed, number of bits, parity, log-on sequences, etc.,  
communications software is typically configured by sessions, each session  
having a unique configuration for a given connection (e.g., to a BBS or  
commercial online service). Most communications programs, however,  
have a separate modem configuration menu because modem  
configurations rarely change from session to session.  
The most important configuration is the modem initialization string. This is  
a sequence of commands the software uses to configure the modem when  
the communications software is loaded or when a session begins. Always  
begin the initialization string with the ATtention command AT, then follow it  
with the modem reset command, &F. Issuing a reset command before  
other commands ensures that you are starting with a known state.  
The rest of the commands in the initialization string depend on the  
capabilities of the modem and what you want it to do. Some older  
communications programs require you to create the initialization string by  
yourself. Most modern communications programs, however, provide you  
with a ready-made initialization string that is automatically selected when  
you choose your modem model from a list. It is a poor idea to use an  
initialization string intended for another modem, especially one from  
another manufacturer, because modem capabilities and command  
implementations vary from modem to modem. However, if your MT2834BR  
does not appear on a modem list, you may use the MultiModemII  
initialization string.  
23  
 
Chapter 3 - Configuration  
3.4  
PC Initialization Strings  
We recommend the following initialization string for a MT2834 connected  
to a PC-compatible computer:  
AT &F X4 S0=0 ^M  
This string resets the MT2834 to the factory default settings, selects  
extended result codes with NO DIAL TONE and BUSY, and turns off auto-  
answer. ^M must end every string sent to the modem from software. It is  
the ASCII code for the RETURN key on most keyboards, and the default  
code for the carriage return character in the MT2834 and most  
communications programs. The carriage return character is defined in the  
MT2834 in S-register S3; if you change it, you must also change the  
carriage return character code used in your communications software. If  
you send a command directly to the modem in terminal mode rather than  
indirectly through communications software, you must end the command  
string by pressing the RETURN key (<CR>) instead of adding ^M to the  
string.  
24  
 
Chapter 3 - Configuration  
Figure 3-2. The MEW Modem Initialization Setup  
* Note that the above and following set up screens are examples found in  
MultiExpress for Windows (MEW), and that other 3rd party data communication  
software is similar but different.  
25  
 
Chapter 3 - Configuration  
3.4.1 Changing Default Parameters  
The default values for the other parameters in modem configuration menus  
rarely need changing. They typically include the dialing prefix (ATDT for  
touch-tone service and ATDP for rotary service), the dialing suffix (^M), the  
hang-up string (+++ATH0^M), and response messages (RING, NO  
CARRIER, BUSY, etc.). Communications software with a host mode might  
also include an auto-answer string (AT S0=1^M).  
3.5  
Macintosh Initialization  
Macintosh computers cannot use RTS/CTS hardware flow control without a  
serial cable wired for hardware control. The Macintosh 128 and 512  
models cannot use RTS/CTS flow control at all. For those Macintoshes  
turn off the default RTS/CTS hardware flow control, turn on XON/XOFF  
flow control and pacing, and ignore DTR:  
AT &F X4 &E5 &E13 &D0 ^M  
For hardware flow control, use the following initialization string:  
AT &F X4 &E13 &D0 ^M  
Add S0=0 to both strings to disable auto-answer if the MT2834BR is on a  
voice line.  
You can store the initialization string in nonvolatile memory. With your  
communications software open and connected to the modem’s COM port,  
type the initialization string in the terminal window, substituting a carriage  
return for ^M. To store the string, enter  
AT &F9 &W0 <CR>.  
Now you can initialize your modem with the following simple string:  
AT Z ^M  
26  
 
Chapter 3 - Configuration  
Configuring Software for Your Computer  
3.6  
Configure the communications software to match the computer’s  
configuration. If the MT2834 is connected to the COM2 serial port, select  
"COM2" under the Device drop-down menu.  
Select the appropriate serial port baud rate. This is the speed the modem  
communicates with the computer, not the speed the modem communicates  
with another modem.  
If V.42bis data compression is enabled, select a serial port baud rate four  
times the transmission speed of the modem to optimize data compression.  
If the UART is fast enough, set the serial port baud rate to a minimum of  
four times the top speed of the modem.  
Figure 3-3. MEW Configuration Parameters Screen  
For an 8250 UART, the most reliable serial port speed is 9600 bps. For an  
8250A or a 16450 UART, try 19,200 bps. For a 16550 UART or equivalent,  
select a serial port setting of 115,200.  
27  
 
Chapter 3 - Configuration  
3.6.1 Configuring Software for the Remote System  
You must meet the requirements of the remote system for successful  
communications. Though the MT2834 can automatically synchronize with  
the speed of the other modem, you must specify parameters such as type  
of flow control, break length, number of data bits, number of stop bits, and  
parity. If you set these parameters incorrectly with the remote system,  
gibberish will appear on your screen.  
3.6.2 Terminal Emulation  
If you are accessing the remote computer as if from an on-site terminal, the  
keyboard codes used by your computer may not match the ones used by  
the remote computer. To be compatible with the remote computer, your  
software must be able to substitute the appropriate codes in what is known  
as terminal emulation. Most communications programs can emulate the  
most common mainframe terminals, including the DEC VT100, VT 102,  
and VT52 terminals, and the basic TTY mode. The following is the  
MultiExpress for Windows Terminal Emulation screen.  
Figure 3-4. MEW Terminal Emulation Setup Screen  
28  
 
Chapter 3 - Configuration  
3.6.3 File Transfer Protocols  
When you upload or download files with your modem, the host computer  
will ask which file transfer protocol you want to use. Most communications  
programs allow you to choose a default protocol. Your software’s  
documentation should list the ones it can use (not all communications  
programs support all protocols). Zmodem is the default protocol in  
MultiExpress for Windows, and we recommend it for most transfers. The  
following is the MEW File Transfer Protocols screen.  
Figure 3-5. MEW File Transfer Protocols Screen  
3.7  
When to Disable Data Compression  
If your serial port cannot keep up because it has an older UART, you may  
lose data when using data compression. Also, the speed advantage  
hardware compression gives you is entirely dependent on how much the  
data being transmitted can be compressed. If the data is already in  
compressed form—a .ZIP or a .SIT file, for example—trying to compress it  
more will actually slow the transmission slightly compared to transmitting  
the same file with compression disabled. This effect will be most noticeable  
if your modem negotiates MNP 5 compression with the other modem.  
V.42bis will not try to further compress a compressed file, but MNP 5 will.  
29  
 
Chapter 3 - Configuration  
The command to disable compression is AT &E14 <CR>. If you have an  
older UART or if you use your modem mostly for downloading long,  
compressed files from BBSs, you may want to include the &E14 command  
in your initialization string as follows:  
AT &F S0=0 X4 &E14 ^M  
As a general rule, you should try to transmit files in already-compressed  
form rather than relying on V.42bis hardware compression. Because  
software compression is more efficient than hardware compression, you  
will have a higher throughput with the former. Of course, this efficiency  
does not include the time spent compressing and decompressing .ZIP or  
.SIT files, but it will save on phone bills. And hardware compression will  
still be there for those occasions when it is inconvenient to compress a file  
with software. Note also that when you download files with compression  
disabled, you can use a slower serial port if you have an older UART.  
3.7.1 Disabling Error Correction  
By default, the MT2834 is set to auto-reliable mode. In this mode the  
MT2834 determines during the handshake whether the other modem is  
using V.42 error correction. If it is, the MT2834 then switches itself to  
reliable mode and enables error correction. If it is not, the MT2834 remains  
in non-error correction mode.  
Normally, we recommend that you leave the MT2834 set to auto-reliable  
mode (&E1). However, you may encounter some circumstances in which  
the MT2834 will work better with error correction turned off. For example, it  
has been reported that on CompuServe error correction will slow file  
transfers at modem speeds of 9600 bps and under. If this is a problem for  
you, you can turn off error correction with the command AT &E0, or you  
can include the command in your initialization string as follows:  
AT &F S0=0 X4 &E0 ^M  
30  
 
Chapter 4 - Modem  
Commands  
 
Chapter 4 - Commands  
4.1  
Modem AT Commands  
AT commands are the means by which you, and your communications  
software, are able to communicate with and configure your modem. They  
enable you to establish, read, and modify parameters in addition to dialing.  
The following provides a summary and brief explanation of the AT  
commands recognized by the MT2834.  
COMMAND:  
VALUES:  
AT  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Attention Code that precedes most command strings  
except A/, A: and Escape Codes.  
COMMAND:  
VALUES:  
Return  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Pressing the RETURN key executes most commands.  
COMMAND:  
VALUES:  
A
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Answer call, even if no ring present.  
COMMAND:  
VALUES:  
$
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
This symbol placed in dialing string enables the modem to  
detect AT&T's "call card" tones to access user's calling  
card to originate an on-line connection.  
COMMAND:  
VALUES:  
A/  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Repeat last command. (Do not precede this command with  
AT. Do not hit RETURN to execute).  
COMMAND:  
VALUES:  
A:  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Continuous redial (10 redials in DOC units) of last number  
until answered. (Not used on International Models).  
32  
 
Chapter 4 - Commands  
COMMAND:  
VALUES:  
DEFAULT:  
$An  
n = 0 or 1  
$A0  
DESCRIPTION:  
$A0 discards data during auto-reliable time period. $A1  
buffers data during auto-reliable time period.  
COMMAND:  
VALUES:  
#An  
n = 0 thru 3  
DEFAULT:  
#A0  
DESCRIPTION:  
#A0 selects initial handshake at 33600 to 31200 to 28800  
to 24000 to 21600 to 19200 to 16800 to 14400 to 12000 to  
9600 to 4800 to 2400 to 1200 to 300 bps.  
#A1 selects initial handshake at 33600 bps only.  
#A2 selects initial handshake at 33600 to 31200 to 28800  
to 24000 to 21600 to 19200 to 16800 to 14400 to 9600 to  
4800 bps.  
#A3 selects initial handshake at 2400 to 1200 to 300 bps.  
COMMAND:  
VALUES:  
Bn  
n = 0 or 1  
DEFAULT:  
B0  
DESCRIPTION:  
B0 selects V.21 for 300 bps operation.  
B1 selects for 300 bps operation (not used on International  
Models).  
COMMAND:  
VALUES:  
&Bn  
n = 0 or 1  
DEFAULT:  
&B0  
DESCRIPTION:  
&B0 selects normal transmit buffer size.  
&B1 selects reduced transmit buffer size.  
COMMAND:  
VALUES:  
&BSn  
n = 0 or 1  
DEFAULT:  
&BS1  
DESCRIPTION:  
&BS0 selects maximum transmit block size of 64  
characters.  
&BS1 selects maximum transmit block size of 256  
characters (MNP mode) or 128 characters (LAP-M mode).  
COMMAND:  
VALUES:  
$BAn  
n = 0 or 1  
DEFAULT:  
$BA0  
DESCRIPTION:  
$BA0 selects speed conversion on.  
$BA1 selects speed conversion off.  
COMMAND:  
&Cn  
33  
 
Chapter 4 - Commands  
VALUES:  
DEFAULT:  
n = 0, 1, 2 or 4  
&C1  
DESCRIPTION:  
&C0 forces Carrier Detect on.  
&C1 lets Carrier Detect act normally.  
&C2 lets Carrier Detect drop S24 time on disconnect.  
&C4 resets modem when Carrier Detect drops.  
COMMAND:  
VALUES:  
&CDn  
n = 0 or 1  
DEFAULT:  
&CD0  
DESCRIPTION:  
&CD0 execute cleardown on disconnect.  
&CD1 do not execute cleardown on disconnect.  
COMMAND:  
VALUES:  
Ds  
s = phone #  
DEFAULT:  
n/a  
DESCRIPTION:  
Dial a telephone number “s”, where s may include up to 60  
digits or T, P, R, comma and ; characters.  
COMMAND:  
VALUES:  
DsNd  
s = phone # and d = 0 thru 9  
DEFAULT:  
n/a  
DESCRIPTION:  
Store telephone number. To store, enter phone number "s",  
followed by N, then Directory Number "d".  
COMMAND:  
VALUES:  
&Dn  
n = 0 thru 3  
DEFAULT:  
&D2  
DESCRIPTION:  
&D0 means DTR is ignored  
&D1 means modem returns to command mode.  
&D2 lets modem react to DTR normally.  
&D3 resets the modem to default parameters.  
COMMAND:  
VALUES:  
$Dn  
n = 0 or 1  
DEFAULT:  
$D0  
DESCRIPTION:  
$D0 disables DTR Dialing.  
$D1 enables DTR Dialing.  
COMMAND:  
VALUES:  
%DF  
n = 0 or 1  
DEFAULT:  
%DF0  
DESCRIPTION:  
%DF0 selects V.34 Line Probe Data in Graph Format.  
%DF1 selects V.34 Line Probe Data in Table Format.  
COMMAND:  
%DP  
34  
 
Chapter 4 - Commands  
VALUES:  
DEFAULT:  
n = 0 or 1  
%DP0  
DESCRIPTION:  
%DP0 selects do not read Line Probe Information from  
DSP during handshaking.  
%DP1 selects read Line Probe Information from DSP  
during handshaking.  
COMMAND:  
VALUES:  
En  
n = 0 or 1  
DEFAULT:  
E1  
DESCRIPTION:  
E0 selects do not echo Command mode characters.  
E1 selects do echo Command mode characters.  
COMMAND:  
VALUES:  
&En  
n = 0 thru 15  
DEFAULT:  
DESCRIPTION:  
&E1, &E4, &E6, &E10, &E13, &E15  
&E0 selects no error correction.  
&E1 selects V.42 Auto-reliable Mode.  
&E2 selects V.42 Reliable Mode.  
&E3 selects no modem-initiated flow control.  
&E4 selects CTS modem-initiated flow control.  
&E5 selects Xon/Xoff modem-initiated flow control.  
&E6 selects Xon/Xoff not passed through.  
&E7 selects Xon/Xoff passed through.  
&E8 selects Enq/Ack pacing off.  
&E9 selects Enq/Ack pacing on.  
&E10 selects Normal Mode flow control off.  
&E11 selects Normal Mode flow control on.  
&E12 selects Pacing off.  
&E13 selects Pacing on.  
E14 selects data compression disabled.  
&E15 selects data compression enabled.  
COMMAND:  
VALUES:  
%En  
n=0 thru 5  
DEFAULT:  
%E1  
DESCRIPTION:  
%E0 = Modem Won’t Escape.  
%E1 = +++ Method (default setting).  
%E2 = Break Method.  
%E3 = Either +++ or Break Method.  
%E4 = No "OK" Response to +++  
%E5 = "OK" Response to +++  
COMMAND:  
#Fn  
35  
 
Chapter 4 - Commands  
VALUES:  
DEFAULT:  
n = 0 thru 2  
#F2  
DESCRIPTION:  
#F0 means no fallback when on-line.  
#F1 means fallback from 33600 to 4800 bps when on-line  
(increments of 2400 bps).  
#F2 means fallback to 4800 bps from 33.6K bps/fall  
forward if line improves (increments of 2400 bps).  
COMMAND:  
VALUES:  
&Fn  
n = 0, 8 or 9  
DEFAULT:  
&F8  
DESCRIPTION:  
&F loads factory default values from ROM.  
&F8 reads factory default values when &F is issued.  
&F9 reads parameters stored in nonvolatile memory when  
&F is issued.  
COMMAND:  
VALUES:  
$Fn  
n = 0 or 1  
DEFAULT:  
$F1  
DESCRIPTION:  
$F0 means do not fall back to normal connect if CR  
received.  
$F1 means fall back to normal connect if CR received.  
COMMAND:  
VALUES:  
$FCn  
n = 0 or 1  
DEFAULT:  
$FC1  
DESCRIPTION:  
$FC0 means no transmit of 5 second 2100Hz signal.  
$FC1 transmits 5 second 2100Hz signal.  
COMMAND:  
VALUES:  
&Gn  
n = 0, 1 or 2  
DEFAULT:  
&G0  
DESCRIPTION:  
&G0 turns off CCITT guard tones.  
&G1 turns on CCITT 550 Hz guard tone.  
&G2 turns on CCITT 1800 Hz guard tone (not used on  
International models).  
COMMAND:  
VALUES:  
Hn  
n = 0 or 1  
DEFAULT:  
n/a  
DESCRIPTION:  
H0 selects Hang Up (go on hook).  
H1 selects Go Off Hook.  
COMMAND:  
$Hn  
36  
 
Chapter 4 - Commands  
VALUES:  
n = 1 thru 3  
DEFAULT:  
Read Only Command  
DESCRIPTION:  
$H1 brings up Help Screen #1.  
$H2 brings up Help Screen #2.  
$H3 brings up Help Screen #3.  
COMMAND:  
VALUES:  
In  
n = 0,1or 2  
DEFAULT:  
DESCRIPTION  
Read Only Command  
I0 requests modem ID #.  
I1 requests firmware revision #.  
I2 for MTS internal use.  
COMMAND:  
VALUES:  
I9  
N/A  
DEFAULT:  
Read Only Command  
DESCRIPTION:  
The I9 command is a query to display this modem's  
characteristics when operating within Windows 95. Entering  
ATI9<cr> invokes BR 28800 FAX CT on your video  
monitor.  
(The response to the query reveals that your  
modem is a BR, 28.8K, FAX and Class Two capable  
device.)  
COMMAND:  
VALUES:  
L
5, 6, 7, 8, 9, 10 and 11  
DEFAULT:  
Read Only Command  
DESCRIPTION:  
Lists all stored telephone numbers in memory.  
L5 lists all current operating parameters.  
L6 lists all current S-Register values.  
L7 lists additional parameters.  
L8 lists current on-line diagnostics.  
L9 displays Signal Strength Information.  
L10 displays Signal to Noise Ratio Information.  
L11 displays Noise Information.  
COMMAND:  
VALUES:  
#Ln  
n = 0 thru 3  
DEFAULT:  
#L0  
DESCRIPTION:  
#L0 selects modems negotiate V.42 Mode.  
#L1 selects MNP on and LAP-M off.  
#L2 selects LAP-M on and MNP off.  
#L3 selects no detection phase; go directly to LAP-M  
mode.  
COMMAND:  
$MBn  
37  
 
Chapter 4 - Commands  
VALUES:  
n = speed  
DEFAULT:  
$MB33600 bps  
DESCRIPTION:  
$MB75 selects CCITT V.23 mode.  
$MB300 selects 300 bps on-line.  
$MB1200 selects 1200 bps on-line.  
$MB2400 selects 2400 bps on-line.  
$MB4800 selects 4800 bps on-line.  
$MB9600 selects 9600 bps on-line.  
$MB14400 selects 14400 bps on-line.  
$MB19200 selects 19200 bps on-line.  
$MB28800 selects 28800 bps on-line.  
$MB33600 selects 33600 bps on-line.  
COMMAND:  
VALUES:  
Nd  
d = 0 thru 9  
DEFAULT:  
n/a  
DESCRIPTION:  
Dial stored telephone number "d" (do not include the letter  
D in this command).  
COMMAND:  
VALUES:  
DEFAULT:  
NdNe  
d = 0 thru 9; e = any other number 0 thru 9  
n/a  
DESCRIPTION:  
Number Linking. If first number dialed is busy, another  
stored number may be automatically dialed. For example, if  
stored number "d" is dialed, and is busy, stored number "e"  
is then dialed.  
COMMAND:  
VALUES:  
O
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Exit Command Mode and go into On-Line Mode.  
COMMAND:  
VALUES:  
P
n/a  
DEFAULT:  
Tone Dial  
DESCRIPTION:  
Modem will pulse-dial numbers following the P.  
COMMAND:  
VALUES:  
&Pn  
n = 0 or 1  
DEFAULT:  
&P0  
DESCRIPTION:  
&P0 selects 60-40 pulse ratio.  
&P1 selects 67-33 pulse ratio.  
COMMAND:  
Qn  
38  
 
Chapter 4 - Commands  
VALUES:  
DEFAULT:  
n = 0, 1 or 2  
Q0  
DESCRIPTION:  
Q0 selects Result Codes displayed.  
Q1 selects Result Codes suppressed (quiet).  
Q2 selects Dumb Answer Mode.  
COMMAND:  
VALUES:  
&Qn  
n = 0 or 1  
DEFAULT:  
&Q0  
DESCRIPTION:  
&Q0 selects Multi-Tech command set.  
&Q1 selects AT command set.  
COMMAND:  
VALUES:  
Rn  
n = 0 or 1  
DEFAULT:  
R0  
DESCRIPTION:  
R0 means modem will not reverse modes.  
R1 means modem will reverse modes.  
COMMAND:  
VALUES:  
&Rn  
n = 0, 1 or 2  
DEFAULT:  
&R1  
DESCRIPTION:  
&R0 lets Clear to Send act normally.  
&R1 forces Clear to Send on.  
&R2 drops for 1 second on disconnect.  
COMMAND:  
VALUES:  
$Rn  
n = 0 or 1  
DEFAULT:  
$R0  
DESCRIPTION:  
$R0 selects disconnect after 12 retransmits.  
$R1 selects do not disconnect after 12 retransmits.  
COMMAND:  
VALUES:  
&RFn  
n = 0 or 1  
DEFAULT:  
&RF1  
DESCRIPTION:  
&RF0 selects CTS follows RTS.  
&RF1 selects CTS to act independently  
COMMAND:  
VALUES:  
DEFAULT:  
Sr=n  
r = 0-11, 13, 15-17, 24-26, 29, 30, 32, 34, 36, 37, 48  
n/a  
DESCRIPTION:  
Sets value of S-Register “r” to value of “n”, where “n” is  
entered in decimal format.  
COMMAND:  
Sr?  
39  
 
Chapter 4 - Commands  
VALUES:  
r = 0-11, 13, 15-17, 24-26, 29, 30, 32, 34, 36, 37, 48  
DEFAULT:  
n/a  
DESCRIPTION:  
Reads value of S-Register “r” and displays value in 3-  
digit decimal format.  
COMMAND:  
VALUES:  
$SBn  
n = speed  
DEFAULT:  
$SB115200 bps  
DESCRIPTION:  
$SB300 selects 300 bps at serial port.  
$SB1200 selects 1200 bps at serial port.  
$SB2400 selects 2400 bps at serial port.  
$SB4800 selects 4800 bps at serial port.  
$SB9600 selects 9600 bps at serial port.  
$SB19200 selects 19200 bps at serial port.  
$SB38400 selects 38400 bps at serial port.  
$SB57600 selects 57600 bps at serial port.  
$SB115200 selects 115200 bps at serial port.  
COMMAND:  
VALUES:  
$SPn  
n = 0 or 1  
DEFAULT:  
$SP0  
DESCRIPTION:  
$SP0 disables UUCP spoofing.  
$SP1enables UUCP spoofing.  
COMMAND:  
VALUES:  
&SFn  
n = 0 or 1  
DEFAULT:  
&SF0  
DESCRIPTION:  
&SF0 selects DSR follows CD.  
&SF1 selects DSR independent.  
COMMAND:  
VALUES:  
&Sn  
n = 0, 1 or 2  
DEFAULT:  
&S1  
DESCRIPTION:  
&S0 forces Data Set Ready On.  
&S1 lets Data Set Ready act normally.  
&S2 Data Set Ready drop is regulated by S24 on  
disconnect.  
COMMAND:  
VALUES:  
T
n/a  
DEFAULT:  
Tone Dial  
DESCRIPTION:  
Modem will tone-dial numbers following the T.  
COMMAND:  
&Tn  
40  
 
Chapter 4 - Commands  
VALUES:  
DEFAULT:  
n = 4 or 5  
&T5  
DESCRIPTION:  
&T4 selects Enable Response to Request for Remote  
Digital Loopback.  
&T5 selects Disable Response to Request for Remote  
Digital Loopback.  
COMMAND:  
VALUES:  
#Tn  
n = 0 or 1  
DEFAULT:  
#T1  
DESCRIPTION:  
#T0 turns off Trellis Coded Modulation  
#T1 turns on Trellis Coded Modulation  
COMMAND:  
VALUES:  
Un  
n = 0, 1, 2, or 3  
DEFAULT:  
n/a  
DESCRIPTION:  
U0 places modem in Analog Loop Originate Mode.  
U1 places modem in Analog Loop Answer Mode.  
U2 places modem in Remote Digital Loopback test mode.  
U3 places modem in Local Digital Loopback Test Mode.  
COMMAND:  
VALUES:  
Vn  
n = 0 or 1  
DEFAULT:  
V1  
DESCRIPTION:  
V0 means Result Codes sent as digits(terse response).  
V1 means Result Codes sent as words (verbose response).  
COMMAND:  
VALUES:  
W
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Wait for new dial-tone.  
COMMAND:  
VALUES:  
&Wn  
n = 0 or 1  
DEFAULT:  
&W1  
DESCRIPTION:  
&W0 causes modem to store its current parameters in non-  
volatile RAM, and modem will load these for future  
sessions instead of reading factory ROM defaults, unless  
&F command used.  
&W1 causes modem to not store parameters.  
COMMAND:  
VALUES:  
Xn  
n = 0, 1, 2, 3 or 4  
41  
 
Chapter 4 - Commands  
DEFAULT:  
X0  
DESCRIPTION:  
X0 selects Basic Result Codes (w/o CONNECT 1200,  
CONNECT 2400).  
X1 selects Extended Result Codes (w/CONNECT 1200,  
CONNECT 2400).  
X2 selects Standard AT Command set with NO DIAL  
TONE.  
X3 selects Standard AT Command set with BUSY.  
X4 selects Standard AT Command set with NO DIAL  
TONE and BUSY.  
COMMAND:  
VALUES:  
#Xn  
n = 0 or 1  
DEFAULT:  
#X0  
DESCRIPTION:  
#X0 selects single XOFF character sent until XON level  
returns.  
#X1 selects multiple XOFF characters after buffer level is  
full.  
COMMAND:  
VALUES:  
Yn  
n = 0 or 1  
DEFAULT:  
Y0  
DESCRIPTION:  
Y0 disables sending or responding to long space “break”.  
Y1 enables sending or responding to long space “breaks”.  
COMMAND:  
VALUES:  
Z
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
All configuration parameters are reset to default values.  
COMMAND:  
VALUES:  
, (Comma)  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Causes pause during dialing.  
COMMAND:  
VALUES:  
;(Semi-Colon)  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Causes return to Command Mode after dialing.  
COMMAND:  
VALUES:  
! (Exclamation)  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Causes modem to flash On-Hook.  
COMMAND:  
VALUES:  
@
n/a  
42  
 
Chapter 4 - Commands  
DEFAULT:  
n/a  
DESCRIPTION:  
Causes modem to wait for ringback, then 5 seconds of  
silence before processing next part of command.  
COMMAND:  
VALUES:  
+++AT<CR>  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
In-band Escape Sequence. Places modem in Command  
mode while still remaining On-Line. Enter +++ followed by  
the letters A and T, up to ten command characters, and a  
RETURN.  
COMMAND:  
VALUES:  
BREAK AT<CR>  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Out-of-band Escape Sequence. Places modem in  
Command mode while still remaining On- Line. Not  
preceded by AT. Enter a BREAK signal, followed by the  
letters A and T, up to sixty command characters, and hit  
RETURN.  
COMMAND:  
VALUES:  
*C <Enter>  
0, 1, 2  
DEFAULT:  
0
DESCRIPTION:  
Caller ID Reporting the Call Traffic Window displays the  
phone number and name of the caller (if the caller's phone  
line supports Caller ID). The call must be answered after  
the second ring to receive the information. This feature  
requires a modem hardware upgrade, Caller Id-enabled  
phone lines, and firmware version greater than 8.07a or  
2.07a. The firmware is disabled by default, enabled by the  
*C command.  
4.1.1 Callback Security Commands  
COMMAND:  
VALUES:  
#DBn  
n= 0, 1, or 2  
DEFAULT:  
DB0  
DESCRIPTION:  
#DB0 disables Callback Security and answering Yes to the  
prompt turns off Callback Security and erases stored phone  
numbers and passwords. Answering No to the prompt  
aborts the command.  
#DB1 activates remote and local password security.  
#DB2 activates remote password security.  
COMMAND:  
VALUES:  
#CBNyyxxxxxx  
n/a  
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Chapter 4 - Commands  
DEFAULT:  
n/a  
DESCRIPTION:  
Callback password with xxxxxx being callback password  
and yy being the memory location. Callback password  
xxxxxx must start with a non-numeric character and upper/  
lower case sensitive. Callback password xxxxxx must be a  
mini mum of 6 and maximum of 10 characters. yy memory  
locations are from 0 to 29. Must T (tone) dialing in string.  
COMMAND:  
VALUES:  
+ - Dxxxxxx???Nxx  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Callback Phone Numbers xxxxxx with the + preceding the  
phone number indicating the callback modem phone  
number for the corresponding password at the same  
memory location. The (-) preceding the phone number  
enables direct entry when the caller uses the correct  
password without the callback modem having to return the  
call. The ??? entry at the end of the phone number  
represents an extension added to the main phone number.  
The Nxx is the memory location of the callback phone  
number and password.  
COMMAND:  
VALUES:  
#Pn  
n= 0, 1, or 2  
DEFAULT:  
#P0  
DESCRIPTION:  
Parity of the prompt messages sent by the callback  
modem.  
#P0 is no parity.  
#P1 is odd parity.  
#P2 is even parity.  
COMMAND:  
VALUES:  
#RCBNxx  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Erases the callback password stored at memory location  
xx. Memory locations are 0 to 29.  
COMMAND:  
VALUES:  
#RDNxx  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Erases the callback phone number stored at memory  
location xx. Memory locations are 0 to 29.  
44  
 
Chapter 4 - Commands  
4.1.2 Remote Configuration  
The Remote Configuration feature is a network management tool that  
allows you to configure modems remotely. This means you could configure  
modems anywhere in your network from one location without having to visit  
the sites or rely on remote users to follow your instructions. With Remote  
Configuration, which is protected by two level security, you can downline  
load new parameters, program new V.42 capabilities and implement new  
features. Remote Configuration also makes troubleshooting a remote  
location a lot easier.  
The way Remote Configuration works is that S-Register S13 has been set-  
up to contain the special Remote Configuration escape code. When  
calling a Remote Configuration equipped modem, you enter the proper  
Remote Escape code to enable entering your Set-up Password. After  
entering it, you can then execute AT commands as if you were connected  
locally. If you set S-Register S13 to zero, Remote Configuration is  
disabled.  
4.1.3 Remote Configuration Procedures  
The procedures for using the Remote Configuration features are the same  
whether or not a call originates from the remote modem. Once the modem  
is on-line, perform the procedure below.  
1. Remote Escape Configuration requires %%%<CR> to be sent if the  
default value in S-Register S13 has not been changed. The modem  
responds with:  
1. - DATA Mode  
2. - COMMAND Mode  
2. You then select 1 or 2. With 1, the modem goes back into data mode  
and with 2, the modem responds with the following:  
Password>  
3. Enter your Set-up Password, and if the code is correct the modem  
responds with:  
OK  
45  
 
Chapter 4 - Commands  
You can now use any AT commands of the modem being remotely  
configured as if they were being entered locally. You cannot change the  
Set-up of the LOGIN Password until you enter the proper LOGIN  
Password.  
4. When you are done entering AT commands and you want to exit, type  
AT0 and hit RETURN. The modem responds with:  
1. DATA Mode  
2. COMMAND Mode  
5. Enter a 1 to go back on-line with your computer, or enter 2 and the  
correct password to talk to your modem.  
Password Commands  
COMMAND:  
VALUES:  
#Ixxxxxxxxxx  
n/a  
DEFAULT:  
#IMULTITECH  
DESCRIPTION:  
Login Password is any keyboard characters (x) (upper/  
lower case sensitive), minimum 6 and maximum 10  
characters. The default Login Password is MULTI-TECH.  
COMMAND:  
VALUES:  
#Syyyyyyyyyy  
n/a  
DEFAULT:  
#SMODEMSETUP  
DESCRIPTION:  
Set-up Password is any keyboard characters (y) (upper/  
lower case sensitive), minimum 6 and maximum 10  
characters. The default Set-up Password is  
MODEMSETUP.  
4.1.4 V.25bis Commands  
COMMAND:  
VALUES:  
$Vn  
n= 0, 1, 2, 5, or 6  
DEFAULT:  
$V0  
DESCRIPTION:  
$V0 returns modem to AT command mode when in V.25bis  
mode.  
$V1 enables V.25bis mode of operation.  
$V2 allows modem to receive one V.25bis command while  
in AT command mode without leaving AT command mode.  
$V5 DSR follows DTR in V.25bis mode.  
$V6 DSR does not follow DTR in V.25bis mode.  
46  
 
Chapter 4 - Commands  
COMMAND:  
VALUES:  
CSPs  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
The CSP command will change the serial baud rate of your  
modem by entering CSPsssss where sssss can equal:  
CSP0300 - 300 bps  
CSP1200 - 1200 bps  
CSP2400 - 2400 bps  
CSP4800 - 4800 bps  
CSP9600 - 9600 bps  
CSP19200 - 19200 bps  
CSP38400 - 38400 bps  
CSP57600 - 57600 bps  
CSP115200 - 115200 bps  
COMMAND:  
VALUES:  
CRNdd  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Dials phone number dd where dd can be up to 20  
characters (0 through 9, *, #, P, T and :). Phone number is  
checked against the Delayed and Forbidden Number lists  
before dialed.  
COMMAND:  
VALUES:  
CRIdd;nn  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
Dials dd same as CRN Command and ignores nn  
identification string.  
COMMAND:  
VALUES:  
DIC or CIC  
n/a  
DEFAULT:  
n/a  
DESCRIPTION:  
The disregard or connect to incoming calls commands are  
used for auto-answer operations. DIC stops the modem  
from answering incoming calls. CIC causes the modem to  
answer incoming calls.  
47  
 
Chapter 4 - Commands  
4.2  
S-Registers  
Certain Command Mode configurations are stored in memory registers  
called, S-Registers. The S command is used to assign a value to, and to  
read the current value of an S-Register.  
To assign a value to an S-Register, enter the letter S, followed by the S-  
Register number and an equals sign (=), and then a decimal response to  
the message “ENTER THE NEW VALUE IN DECIMAL FORMAT”.  
To read an S-Register value, enter the letter S followed by the S-Register  
number and a question mark (?), then hit RETURN. To verify that the S-  
Register value was entered correctly, enter for example, ATS8? and hit  
RETURN. You should receive a response of the assigned value given to  
that S-Register.  
S0  
Number of Rings Until Modem Answers  
Unit:  
1 ring  
Range:  
Default:  
Description:  
0-255  
1
Sets the number of rings before the modem answers.  
S1  
Rings Which Have Occurred  
Unit:  
1 ring  
Range:  
Default:  
Description:  
0-255  
0
Counts the number of rings that have occurred.  
S2  
Escape Code Character  
Unit:  
ASCII Character  
Range:  
0-127  
Default:  
43 (+ sign)  
Description:  
Defines the escape code character.  
S3  
Return Character  
Unit:  
ASCII Character  
Range:  
0-127  
Default:  
13  
Description:  
Defines the character recognized as Carriage Return  
(RETURN) or “Enter”.  
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Chapter 4 - Commands  
S4  
Line Feed Character  
Unit:  
ASCII Character  
Range:  
Default:  
0-127  
10  
Description:  
Defines the character recognized as LINE FEED.  
S5  
Backspace Character  
Unit:  
ASCII Character  
Range:  
0-127  
Default:  
8
Description:  
Defines the character recognized as BACKSPACE.  
S6  
Wait Time for Dial Tone  
Unit:  
1 second  
Range:  
2-255, 4-255**  
Default:  
2, 4**  
Description:  
Sets the time the modem waits after the RETURN key is  
pressed before executing a dial command.  
S7  
Time for Carrier (Abort Timer)  
Unit:  
1 second  
Range:  
Default:  
Description:  
1-255, 1-45*  
45  
Defines the Abort Timer (lack of carrier) delay time.  
S8  
Pause Time for Comma  
Unit:  
1 second  
Range:  
0-255, 4-255**  
Default:  
2, 4**  
Description:  
Sets the length of the pause caused by a comma inserted  
in a dialing commarnational and DOC units  
S9  
Carrier Detect Response Time  
Unit:  
100 mSec.  
Range:  
Default:  
Description:  
1-255  
6
Sets the time delay for when the modem first detects a  
valid incoming carrier signal and when the modem turns on  
its Carrier Detect circuit.  
** Value for International Units only  
49  
 
Chapter 4 - Commands  
S10  
Carrier Loss Disconnect Delay Time  
Unit:  
100 mSec.  
Range:  
Default:  
Description:  
0-255  
7
Sets the time a carrier signal must be lost before the  
modem disconnects.  
S11  
Tone Dialing: Tone Spacing and Duration  
Unit:  
1 mSec.  
Range:  
Default:  
Description:  
1-255, 80-255*  
70, 80*  
Sets the time duration of spacing between tone in tone-  
dialing.  
S13  
Remote Configuration Escape Character  
Unit:  
ASCII Character  
Range:  
Default:  
Description:  
0-127  
37 (% sign)  
Defines the remote configuration escape character.  
S16  
Callback Attempts  
Unit:  
1 Attempt  
Range:  
1-255  
Default:  
4
Description:  
S16 defines the number of attempts allowed after initial  
passwords have been exchanged between modems.  
S17  
Changing Break Time  
Unit:  
10 mSec.  
Range:  
0-2.5 sec  
Default:  
250  
Description:  
S17 defines the break time (space) to local PC.  
S24  
PBX/CBX Disconnect Drop Time for DSR/CTS/CD  
Unit:  
50 mSec.  
Range:  
Default:  
Description:  
0-255  
20  
Defines DSR/CTS/CD dropout time. The default of 20  
equals one second.  
50  
 
Chapter 4 - Commands  
S25  
DTR Dropout Time  
Unit:  
100 mSec.  
Range:  
Default:  
0, 1 through 255  
0
Description:  
Defines DTR dropout time. 0 default equals 50ms.  
S26  
Failed Password Attempts  
Unit:  
1 failed attempt  
Range:  
Default:  
Description:  
0-255  
0
Counts the number of times there has been a failed  
password attempt.  
S29  
Local Inactivity Timer  
Unit:  
minutes  
Range:  
1-255  
Default:  
20  
Description:  
Defines the amount of idle time that can elapse between  
AT commands after the SETUP password has been  
entered.  
S30  
Inactivity Timer  
Unit:  
1 minute  
Range:  
0-255  
Default:  
0
Description:  
Inactivity timer used to disconnect the modem.  
S32  
Time Elapse for Escape Sequence  
Unit:  
1 second  
Range:  
Default:  
Description:  
0-255  
20  
Sets the duration in which modem waits for a <CR> to be  
entered during escape sequence execution.  
S34  
Buffer Length of Command Mode...After On-line Escape Sequence  
Unit:  
ASCII Character  
Range:  
Default:  
Description:  
0-60  
10  
Sets buffer length of command mode after on-line escape  
sequence.  
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Chapter 4 - Commands  
S36  
Time Between DTR Inactive and Modem Off-Hook  
Unit:  
1 Second  
Range:  
Default:  
Description:  
0-255 seconds  
0
Sets the time between DTR inactive (low) and the modem  
going off-hook. The DTR Busy-out feature is disabled with  
S36=0.  
S37  
Time Between DTR Active and Modem On-Hook  
Unit:  
1 Second  
Range:  
Default:  
Description:  
0-255 seconds  
5
Sets the time between DTR being active and the modem  
going on-hook (not busy).  
S48  
Program V34 Connect Speeds  
Unit:  
N/A  
Range:  
Default:  
Description:  
33, 31, 28, 26, 24, 21,19,16,14,12, 96 and 48  
0
Defines which speed modem connects within Enhanced  
V.34 mode scope (e.g., S48 = 21 means maximum connect  
speed is 21.6K). This register is when line conditions will  
not support higher Enhanced V.34 speeds (e.g., 33.6K,  
31.2K, 28K, 26.4K, 24K...) The modem default is a value  
of 0, which indicates a connection attempt of 33.6K.  
4.3  
Result Codes  
The MT2834BR Command mode provides you with several responses, or  
“Result Codes”, that can aid you in Command mode operation. These  
Result Codes are displayed on your video monitor.  
AT&Q0  
Selects Multi-Tech responses with Reliable/Compression  
modifiers. The terse result code for CONNECT 2400 is 9.  
AT&Q1  
selects Standard AT command set responses. The terse  
result code for CONNECT 2400 is 10.  
Table 4-1: &Q0 "Multi-Tech" Result Codes  
52  
 
Chapter 4 - Commands  
TERSE VERBOSE  
0
OK  
1
CONNECT  
2
RING  
3
NO CARRIER  
ERROR  
4
5 *  
6
CONNECT 1200  
NO DIALTONE  
BUSY  
7
8
NO ANSWER  
CONNECT 2400  
CONNECT 4800  
CONNECT 9600  
CONNECT 14400  
CONNECT 19200  
CONNECT 21600  
CONNECT 24000  
CONNECT 26400  
CONNECT 28800  
CONNECT 31200  
CONNECT 33600  
9 *  
11 *  
12 *  
13 *  
19 *  
21 *  
24 *  
26 *  
28 *  
31 *  
33 *  
* With MNP error correction on, RELIABLE (or R) is added to these result codes.  
With LAP-M error correction on, LAP-M (or L) is added to these result codes.  
With data compression on, COMPRESSED (or C) is added. (Note these  
"Extended" Result Codes are displayed when your modem is set-up to do so  
with an X1, X2, X3, or X4 command.)  
Table 4-2: &Q1 "Standard AT" Result Codes  
53  
 
Chapter 4 - Commands  
TERSE VERBOSE  
0
OK  
1
CONNECT  
2
RING  
3
NO CARRIER  
ERROR  
4
5
CONNECT 1200  
NO DIAL TONE  
BUSY  
6
7
8
NO ANSWER  
CONNECT 2400  
CONNECT 4800  
CONNECT 9600  
CONNECT 14400  
CONNECT 19200  
CONNECT 21600  
CONNECT 24000  
CONNECT 26400  
CONNECT 28800  
CONNECT 31200  
CONNECT 33600  
10  
11  
12  
13  
19  
21  
24  
26  
28  
31  
33  
* Error Correction/Data Compressed modifiers are not displayed with Standard  
AT Result Codes.  
54  
 
Chapter 4 - Commands  
4.3.1 AT Commands and S-Register Summary  
The vast majority of installations are similar, with the MT2834 being used  
to dial up a remote installation where the call is automatically answered.  
Your MT2834 has a default configuration to dial another 33,600 bps  
modem that support error correction, data compression and flow control. If  
the answering modem is not compatible, the MT2834 can match protocols,  
provided the protocols are industry standard (i.e., ITU-T or Bell) and not  
proprietary.  
The &W command, used in conjunction with specific other AT commands  
and S-Registers, can reconfigure the MT2834 to conform to a specific  
application. The MT2834 can store its configuration parameters and S-  
Register values in its nonvolatile memory.  
The command AT&W0 (or AT&W) causes the modem to store its current  
parameters in its nonvolatile RAM. The command also sets the modem  
upon power up, or when it is reset with an ATZ command, the modem  
reads all its configuration and S-Register parameters from RAM, and not  
from the factory settings in ROM (note you may recall factory installed  
defaults by entering AT&F8&W0). The &W command changes the  
configuration parameters stored in RAM that you specifically intend to alter.  
All other default parameters remain unchanged.  
The AT&W1 command sets the modem so that it does not store its  
parameters in RAM, and on power up or when an ATZ command is issued,  
parameters are read from the factory default settings in ROM.  
Before using the &W command, you may want to view the modem's  
current operating parameters. Use the ATL5, ATL6 and ATL7 commands  
to display the current modem configuration.  
55  
 
Chapter 5 - Modem Testing  
 
Chapter 5 - Testing the Modem  
Local Analog Loopback Test/V.54 Loop 3  
5.1  
In this test, data from your computer or terminal is sent to your modem's  
transmitter, converted into analog form, looped back to the receiver,  
converted into digital form and then received back at your monitor for  
verification. No connection to the phone line is required. See Figure 5-1.  
Computer or Terminal  
Local MultiModem  
UUUU  
Digital  
Analog  
Type ATU0 or ATU1,  
then ENTER  
Figure 5-1. Local Analog Loopback Test  
The test procedure is as follows:  
1. Connect the modem to your computer. With your communication  
software, set the desired baud rate.  
2. Type ATU0 (or ATU) and hit ENTER. This places your modem in  
Analog Loopback mode, in the Originate mode. The modem is now out  
of the Command mode and in a pseudo On-Line mode.  
3. Once you receive a connect message (if responses are enabled), enter  
data from your keyboard. For this test, typing multiple upper case "U"  
characters is a good way to send an alternating test pattern of ones and  
zeros.  
4. For a more complete test, you should also test the modem in Answer  
mode. To do this, you must “escape” from Originate mode by entering  
an Escape Sequence (+++AT<CR> or <BREAK>AT<CR>) . Then type  
57  
 
Chapter 5 - Testing the Modem  
ATU1 and hit ENTER to place the modem in Analog Loopback mode, in  
the Answer mode. Then repeat step 3.  
5. When testing is completed, you may exit Answer mode by entering an  
Escape Sequence (+++AT<CR> or <BREAK>AT<CR>), which returns  
the modem to Command mode.  
6. Your modem passes this test if the data entered from your keyboard are  
the same as the data received on your monitor. If different data is  
appearing on your monitor, your modem is probably causing the  
problem, although it could also be your computer. If your modem  
passes this test, but you are receiving errors while On-line, the remote  
modem or the phone line could be at fault.  
5.2  
Digital Loopback Test/V.54 Loop 2 (Local/Manual)  
The Digital Loopback Test is an on-line test that loops data sent from one  
modem across the phone line to another modem, then back to the first  
modem. See Figure 5-2.  
There are two ways to put a modem into Digital Loopback mode.  
1. Locally or Manually, described here in section 5.2.  
2. Remotely or Automatically, see section 5.3.  
Note: Loopback tests operate at all speeds except 300 bps. Disable error  
correction (&E0&W0<CR>) before engaging in loopback tests.  
In this test the local modem is placed in Digital Loopback mode. Data is  
entered and transmitted from the remote modem (which is not in digital  
loopback mode), sent across the phone line to the local modem and  
looped back to the remote modem.  
The test procedure is as follows:  
1. Go into Terminal mode. Type AT and hit ENTER; you should get an OK  
message.  
58  
 
Chapter 5 - Testing the Modem  
2. Dial the remote modem by entering the Dial command and the phone  
number, to establish On-line mode.  
3. Type the Escape Sequence (+++AT<CR> or <BREAK>AT<CR>) which  
brings your modem into Command mode, while still maintaining the  
pseudo On-line mode with the remote modem.  
4. Type ATU3 from the local PC and hit ENTER. Once you receive an OK  
message from your modem (if responses are enabled), the local  
modem is placed in Digital Loopback mode.  
5. Data is typed from the remote keyboard. For this test, typing multiple  
upper case "U" characters is a good way to send an alternating test  
pattern of ones and zeros. The data received by the local modem will  
enter its analog receiver, be converted to digital data, be reconverted  
into analog, and then looped through its transmitter back to the remote  
modem. Your modem passes this test if the data entered from the  
remote keyboard is the same as the data received on the remote  
monitor.  
Computer or Terminal  
Computer or Terminal  
UUUU  
Local Modem  
Remote Modem  
Digital Analog  
Analog  
Digital  
Figure 5-2. Digital Loopback Test (local / manual)  
6. When testing is complete, you may end the test by typing an Escape  
Sequence (+++AT<CR> or <BREAK>AT<CR>) to bring your modem  
into Command mode. The modem should respond with an OK  
message. If you wish to stay On-line with the remote modem for normal  
data transmission, type AT0 and hit ENTER. If you wish to terminate  
the call, type ATH and hit ENTER to hang up.  
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Chapter 5 - Testing the Modem  
5.3  
Digital Loopback Test/V.54 Loop 2  
(Remote/Automatic)  
In this test, your modem must be On-line with another modem set up to  
respond to a request for Digital Loopback. The test is as follows:  
1. Enter Terminal mode.Type AT and hit ENTER. An OK message  
displays.  
2. Dial the remote modem by entering the Dial command and the phone  
number, to establish On-line mode.  
Note:  
Set the &T4 command on the remote modem prior to running test.  
3. Type the Escape Sequence (+++AT<CR> or <BREAK>AT<CR>) to  
enter Command mode, maintaining the remote modem connection.  
4. Type ATU2 and hit ENTER. The local modem transmits an  
unscrambled marking signal. The remote modem enters Digital  
Loopback mode. The local modem exits Command mode and enters  
pseudo On-line mode.  
5. Type multiple uppercase "U" characters to send an alternating test  
pattern of ones and zeros. The data received by the remote modem  
enters the analog receiver and is converted to digital data. The data is  
reconverted into analog, then looped through the transmitter back to the  
local modem. If the data entered from the keyboard is the same as the  
data received on the monitor, the modem has passed the test.  
Computer or Terminal  
Computer or Terminal  
UUUU  
Local Modem  
Remote Modem  
Digital Analog  
Analog Digital  
Figure 5-3. Digital Loopback Test (remote / automatic)  
60  
 
Chapter 5 - Testing the Modem  
5.4  
Local Analog Loopback Test (Synchronous Mode)  
To initiate the Local Analog Loopback Test, with the modem in  
Synchronous mode:  
1. Enter AT&M1U. This first switches your modem from asynchronous to  
synchronous mode, and places it into the Analog Loopback/Originate  
mode. The modem is now out of the Command mode and in the  
pseudo On-Line mode.  
2. Once you receive a connect message (if responses are enabled), enter  
data from your keyboard. For this test, typing multiple upper case "U"  
characters is a good way to send an alternating test pattern of ones and  
zeros.  
3. For a more complete test, you should also test the modem in Answer  
mode. To do this, pull out and then reinsert modem card in rack cage.  
Then type AT&M1U1 and hit ENTER to place the modem in Analog  
Loopback mode, in the Answer mode. Then repeat step 2.  
Computer or Terminal  
Local MultiModem  
UUUU  
Digital  
Analog  
Figure 5-4. Local Analog Loopback Test (Syncronous Mode)  
61  
 
Chapter 5 - Testing the Modem  
5.5  
Digital Loopback Test (Local/Manual)  
(Synchronous Mode)  
This test must be run when you have a data connection with another  
modem. To initiate the Digital Loopback Test (local/manual), DIP-Switch #9  
must be in the UP position, then place DIP-Switch #16 in the opposite  
position it is currently (the modem requires a state of change in Switch #16  
to activate Loopback tests). Once you receive an OK message from your  
modem (if responses are enabled), the local modem is placed in Digital  
Loopback mode.  
To exit the Digital Loopback Test (local/manual), pull out and then reinsert  
modem card into modem card cage.  
Computer or Terminal  
Computer or Terminal  
UUUU  
Local Modem  
Remote Modem  
Digital Analog  
Digital  
Analog  
Figure 5-5. Digital Loopback Test  
(local / manual) (Syncronous)  
62  
 
Chapter 5 - Testing the Modem  
5.6  
Digital Loopback Test (Remote/Automatic)  
(Synchronous Mode)  
This test must be run when you have a data connection with another  
modem. To initiate the Digital Loopback Test (remote/automatic), DIP-  
Switch #9 must be in the DOWN position, then place DIP-Switch #16 in the  
opposite position it is currently (the modem requires a state of change in  
Switch #16 to activate Loopback tests). Once you receive an OK message  
from your modem (if responses are enabled), the local modem is placed in  
Digital Loopback mode.  
To exit the Digital Loopback Test (remote/automatic), pull out and then  
reinsert modem card into modem card cage.  
Computer or Terminal  
Computer or Terminal  
UUUU  
Local Modem  
Digital Analog  
Remote Modem  
Analog Digital  
Figure 5-6. Digital Loopack Test  
(remote / automatic) (Syncronous)  
63  
 
Chapter 6 - Warranty  
and Service  
 
Chapter 6 - Warranty and Service  
6.1  
Introduction  
This chapter starts out with statements about your modem's 2-year  
warranty. The next section, Tech Support, should be read carefully if you  
have questions or problems with your modem. It includes the technical  
support telephone numbers, space for recording your modem information,  
and an explanation of how to send in your modem should you require  
service. The final five sections explain how to use our Bulletin Board  
Service (BBS), upgrading the MT2834BR via Flash PROM, a Safety  
Warnings notice, a brief section on the CompuServe/Internet Forums and  
information on Multi-Tech's Fax-Back service.  
6.2  
Limited Warranty  
Multi-Tech Systems, Inc. (“MTS”) warrants that its products will be free  
from defects in material or workmanship for a period of two years from the  
date of purchase, or if proof of purchase is not provided, two years from  
date of shipment. MTS MAKES NO OTHER WARRANTY, EXPRESSED  
OR IMPLIED, AND ALL IMPLIED WARRANTIES OF MERCHANTABILITY  
AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY  
DISCLAIMED. This warranty does not apply to any products which have  
been damaged by lightning storms, water, or power surges or which have  
been neglected, altered, abused, used for a purpose other than the one for  
which they were manufactured, repaired by the customer or any party  
without MTS’s written authorization, or used in any manner inconsistent  
with MTS’s instructions.  
MTS’s entire obligation under this warranty shall be limited (at MTS’s  
option) to repair or replacement of any products which prove to be  
defective within the warranty period, or, at MTS’s option, issuance of a  
refund of the purchase price. Defective products must be returned by  
Customer to MTS’s factory transportation prepaid.  
MTS WILL NOT BE LIABLE FOR CONSEQUENTIAL DAMAGES AND  
UNDER NO CIRCUMSTANCES WILL ITS LIABILITY EXCEED THE  
PURCHASE PRICE FOR DEFECTIVE PRODUCTS.  
65  
 
Chapter 6 - Warranty and Service  
6.3  
Tech Support  
Multi-Tech has an excellent staff of technical support personnel available  
to help you get the most out of your Multi-Tech product. If you have any  
questions about the operation of this unit, call 1-800-972-2439. Please fill  
out the modem information (below), and have it available when you call. If  
your modem requires service, the tech support specialist will guide you on  
how to send in your modem (see Section 6.3.2).  
6.3.1 Recording Modem Information  
Please fill in the following information on your Multi-Tech modem. This will  
help tech support in answering your questions.  
Modem Model No.: ___________________________________  
Modem Serial No.: ____________________________________  
Modem Firmware Version: _____________________________  
COM Port#: _________________________________________  
FAX Software Type and Version: ________________________  
DataComm Software Type and Version: __________________  
The modem model and serial numbers are silkscreened on the bottom of  
your modem. The software version is printed on the System CD label. Type  
ATI1 to display the modem firmware version.  
Please note the status of your modem before calling tech support. This  
status can include LED indicators, screen messages, diagnostic test  
results, problems with a specific application, etc..  
6.3.2 Service  
If your tech support specialist decides that service is required, modems  
may be sent (freight prepaid) to our factory. Return shipping charges will  
be paid by Multi-Tech Systems.  
Include the following with your modem:  
• a description of the problem.  
• return billing and return shipping addresses.  
• contact name and phone number.  
66  
 
Chapter 6 - Warranty and Service  
• check or purchase order number for payment if the modem is out of  
warranty. (Check with your technical support specialist for current  
charges.)  
• if possible, note the name of the technical support specialist with whom  
you spoke.  
If you need to inquire about the status of the returned product, be prepared  
to provide the serial number of the product sent (see Section 6.3.1).  
Send modems to this address:  
MULTI-TECH SYSTEMS, INC.  
2205 WOODALE DRIVE  
MOUNDS VIEW, MINNESOTA 55112  
ATTN: SERVICE OR REPAIRS  
6.4  
Upgrading the MT2834BR  
The MT2834BR has a Flash PROM which contains firmware code for the  
hardware and DSP code for the digital signal processor chips. At various  
times, Multi-Tech may add enhancements and/or fixes to the firmware. The  
flash technology used in the MT2834BR lets you load these upgrades into  
the PROM or DSP chips through the modem's serial port.  
6.4.1 Using FlashPro to Upgrade Modem Firmware  
1. Download FLASHPRO.ZIP and a new .HEX file from the Multi-  
Tech BBS.  
2. Unzip the FLASHPRO.ZIP file. Place this unzipped file and the  
.HEX file in the same directory.  
3. Run FlashPro by typing FLASHPRO, a space, -M and hitting ENTER at  
the DOS prompt.  
4. Highlight the "Configure" option in the MAIN MENU and hit  
ENTER. Highlight "Active Port" and select the COM port to  
which you have your modem attached. Highlight "Baud Rate"  
67  
 
Chapter 6 - Warranty and Service  
and select the rate you want to program at. Hit ESC when  
finished.  
5. Highlight the "Select File to Program" option in the MAIN  
MENU. Highlight the .HEX file. Hit ESC when finished.  
6. Highlight "Program Firmware" option in the MAIN MENU. When you are  
prompted to confirm the file to program, press "Y".  
7. If you need more assistance programming FLASHPRO, then contact our  
tech support department.  
6.5  
Safety Warnings  
1. Never install telephone wiring during a lightning storm.  
2. Never install telephone jacks in wet locations unless the jack is  
specifically designed for wet locations.  
3. Never touch uninsulated telephone wires or terminals unless the  
telephone line has been disconnected at the network interface.  
4. Use caution when installing or modifying telephone lines.  
5. Avoid using a telephone (other than a cordless type) during an  
electrical storm. There may be a remote risk of electrical shock from  
lightning.  
6. Do not use the telephone to report a gas leak in the vicinity of the leak.  
7. Ports which are connecting to other apparatus are defined as SELV.  
To ensure conformity with EN 41003, ensure that these ports are only  
connected to the same type on other apparatus.  
68  
 
Chapter 6 - Warranty and Service  
6.6  
Internet  
Multi-Tech is a commercial provider on the Internet, and we retrieve  
e-mail messages from the following mailboxes on a periodic basis:  
Technical Support  
Marketing Dept.  
Sales Dept.  
International Sales Dept.  
Publications Dept.  
Multi-Tech's presence includes a Web site at:  
69  
 
Chapter 7 - BABT  
Requirements  
 
Chapter 7 - BABT Requirements  
Compliance with BABT Requirements  
7.1  
Approved for connection to telecommunications system specified in the  
instructions for use subject to the conditions set out in them.  
Warning: Interconnection directly, or by way of other apparatus, of ports  
marked "SAFETY WARNING see instructions for use" with ports marked or  
not so marked may produce hazardous conditions on the network. Advice  
should be obtained from a competent engineer before such a connection is  
made.  
This apparatus has been approved for the use of the following facilities:  
• Auto-calling  
• Loop disconnect and MF dialing  
• Phone number storage and retrieval by a predetermined code  
• Operation in the absence of proceed indication  
• Automatic storage of last number dialed  
• Tone detection-busy  
• Auto clear from the originating end  
• DTR dialing  
• Modem  
• PBX timed break register recall  
71  
 
Chapter 7 - BABT Requirements  
7.1.1 European Low Voltage Directive  
When correctly installed and maintained, the modem will present no  
hazard to the user. When correctly installed the modem will be connected  
to the PSTN or a PW and to a Data Terminal Equipment (DTE), whose  
modem connections comply with CCITT recommendation V28. The DTE  
connections are therefore taken to be safe voltages (less than ± 30 volts).  
The main power source shall be installed near to the equipment and shall  
be easily accessible. The plug that connect to the apparatus to the main  
power supply must be fitted with a 5A fuse that complies with BSI1362.  
Ports which are capable of connecting to other apparatus are defined as  
SELV. To ensure conformity with EN 41003, ensure that these ports are  
only connected to ports of the same type on other apparatus.  
7.1.2 Compliance with BS6305 Clause 6.2, BS6320  
Clause 7.2, and BABT/SITS/82/005S/D  
a. The modem is suitable for connection to the Public Switched Telephone  
Network (PSTN) provided by British Telecommunications plc or  
Kingston Communications (Hull) plc. Circuit supply by British  
Communications, Mercury Communication, or Hull City Council. Only  
direct exchange lines may be used, not shared service.  
b. The modem is suitable for household, office, and similar general indoor  
use. It is not suitable for use as an extension to a payphone.  
c. BT lines supplied must support either loop disconnect or multifrequency  
tone signalling.  
d. REN (Ringer Equivalence Number).  
The REN value of a unit is calculated from 3/n where n is the total number  
of units which can be connected in parallel which will still cause the  
standard bell (as defined in BS6305 Appendix D) to ring.  
REN values of less than 0.3 cannot be assigned.  
REN = 1  
72  
 
If a telephone or other device is connected in parallel with the modem, the  
combined REN must not exceed 4. A BT supplied telephone may be  
assumed to have REN of 1.0 unless otherwise noted.  
The approval of this modem for connection to the British Telecom public  
switched telephone network is INVALIDATED if the apparatus is subject to  
any modification in any material way not authorized by BABT or if it is used  
with or connected to:  
i. internal software that has not been formally accepted BABT.  
ii. external control software or external control apparatus which cause the  
operation of the modem associated call set-up equipment to contravene  
the requirements of the standard set out in BABT/SITS/82/005S/D.  
All other apparatus connected to this modem and thereby connected  
directly or indirectly to the British Telecom public switched telephone  
network must be approved apparatus as defined in Section 22 of the  
British Telecommunications Act 1984.  
The REN number for this apparatus = 1  
7.1.3 Compliance with BS6789: Section 3.1 and Part 2  
a. The modem is not capable of allowing Auto Call using '999' or other PABX  
emergency numbers.  
b. Modes other than modes 1, 2, or 3 should not be used on the BT PSTN.  
This modem is a mode 1 device.  
c. Users are advised to check the numbers entered during the Auto Call set  
up phase prior to dialing.  
d. The user should not issue any sequence of commands to the modem  
which would cause the modem to exceed the maximum allowable pause  
of 8 seconds from the time the modem goes off hook until dialing begins.  
e. For correct operation of the call progress monitor, the power has to be  
properly connected and switched on.  
 
Chapter 7 - BABT Requirements  
7.1.4 Compliance with BS6328 Part 1  
a. The modem is not suitable for use on circuits with British  
Telecommunications signaling at a normal frequency of 2280 Hz.  
b. The modem does not require signaling or otherwise employ the frequency  
range dc to 200 Hz.  
c. The modem may be connected to a point to point two-wire or four-wire  
Private Circuit.  
d. The modem does not require dc from the Private Circuit for correct  
operation. The modem may be damaged if connected, in a private circuit  
mode, to a circuit supplying dc current (the maximum permissible direct  
current is zero amps).  
74  
 
Appendices  
 
Appendix A  
Appendix A  
FCC Regulations for Telephone Line Interconnection  
1. This equipment complies with Part 68 of the Federal Communications  
Commission (FCC) rules. On the outside surface of this equipment is a  
label that contains, among other information, the FCC registration  
number and ringer equivalence number (REN). If requested, this  
information must be provided to the telephone company.  
2. As indicated below, the suitable jack (Universal Service Order Code  
connecting arrangement) for this equipment is shown. If applicable, the  
facility interface codes (FIC) and service order codes (SOC) are shown.  
An FCC-compliant telephone cord and modular plug is provided with  
this equipment. This equipment is designed to be connected to the  
telephone network or premises wiring using a compatible modular jack  
which is Part 68 compliant. See installation instructions for details.  
3. The ringer equivalence number (REN) is used to determine the quantity  
of devices which may be connected to the telephone line. Excessive  
REN’s on the telephone line may result in the devices not ringing in  
response to an incoming call. In most, but not all areas, the sum of the  
REN’s should not exceed five (5.0). To be certain of the number of  
devices that may be connected to the line, as determined by the total  
REN’s, contact the telephone company to determine the maximum REN  
for the calling area.  
4. If this equipment causes harm to the telephone network, the telephone  
company will notify you in advance that temporary discontinuance of  
service may be required. But if advance notice isn’t practical, the  
telephone company will notify the customer as soon as possible. Also,  
you will be advised of your right to file a complaint with the FCC if you  
believe it is necessary.  
76  
 
Appendix A  
5. The telephone company may make changes in its facilities, equipment,  
operations, or procedures that could affect the operation of the  
equipment. If this happens, the telephone company will provide  
advance notice in order for you to make necessary modifications in  
order to maintain uninterrupted service.  
6. If trouble is experienced with this equipment (the model of which is  
indicated below) please contact Multi-Tech Systems, Inc. at the address  
shown below for details of how to have repairs made. If the equipment  
is causing harm to the telephone network, the telephone company may  
request you remove the equipment from the network until the problem  
is resolved.  
7. No repairs are to be made by you. Repairs are to be made only by  
Multi-Tech Systems or its licensees. Unauthorized repairs void  
registration and warranty.  
8. This equipment cannot be used on public coin service provided by the  
telephone company. Connection to Party Line Service is subject to  
state tariffs. (Contact the state public utility commission, public service  
commission or corporation commission for information.)  
9. If so required, this equipment is hearing-aid compatible.  
Manufacturer:  
Model Number:  
FCC Registration #:  
Multi-Tech Systems, Inc.  
MT2834BR  
AU7USA-20673-MM-E  
Ringer Equivalence: 0.3B  
Modular Jack (USOC) RJ11C or RJ11W (single line)  
Service Center in US: Multi-Tech Systems Inc.  
2205 Woodale Drive  
Mounds View, MN 55112  
Voice (763) 785-3500  
FAX (763) 785-9874  
77  
 
Appendix A  
Canadian Limitations Notice  
Notice: The ringer equivalence number (REN) assigned to each terminal  
device provides an indication of the maximum number of terminals allowed  
to be connected to a telephone interface. The termination of a interface  
may consist of any combination of devices subject only to the requirement  
that the sum of the ringer equivalence numbers of all the devices does not  
exceed 5.  
Notice: The Industry Canada label identifies certificated equipment. This  
certification means that the equipment meets certain telecommunications  
network protective, operational and safety requirements. The Industry  
Canada does not guarantee the equipment will operate to the user’s  
satisfaction.  
Before installing this equipment, users should ensure that it is permissible  
to be connected to the facilities of the local telecommunications company.  
The equipment must also be installed using an acceptable method of  
connection. The customer should be aware that compliance with the above  
conditions may not prevent degradation of service in some situations.  
Repairs to certified equipment should be made by an authorized Canadian  
maintenance facility designated by the supplier. Any repairs or alterations  
made by the user to this equipment, or equipment malfunctions, may give  
the telecommunications company cause to request the user to disconnect  
the equipment.  
Users should ensure for their own protection that the electrical ground  
connections of the power utility, telephone lines and internal metallic water  
pipe system, if present, are connected together. This precaution may be  
particularly important in rural areas.  
Caution: Users should not attempt to make such connections themselves,  
but should contact the appropriate electric inspection authority, or  
electrician, as appropriate.  
78  
 
Appendix B  
Appendix B  
Technical Specifications  
Your MT2834BR/BRL data/fax modem meets the specifications listed  
below:  
Model Numbers  
MT2834BR, MT2834BRI, MT2834BR-MAC  
Data Rates (modem)  
33600, 31200, 28800, 26400, 24000, 21600,  
19200, 16800, 14400, 12000, 9600, 7200,  
4800, 2400, 1200, 0-300 bps  
Data Rates (fax)  
Data Format  
14400, 9600, 7200, 4800 bps  
Serial, binary, asynchronous at 0-300, 1200,  
2400, 4800 , 7200, 9600, 14400, 16800, 19200,  
21600, 24000, 26400, 28800, 31200, 33600  
bps; synchronous at 1200, 2400, 4800, 7200,  
9600, 14400, 16800, 19200, 21600, 24000,  
26400, 28800, 31200, 33600 bps  
Compatibility  
ITU V.42bis, V.42, Pending ITU Enhanced V.34  
approval, V.34, ITU V.32bis, V.32, V.21*,  
V.22bis, V.22, V.23*,V.25bis, Bell 212A and  
103/113, ITU V.17, Group 3 T.4, T.30 and EIA  
TR-29 Class 2 (*V.21/V.23 Int'l models only)  
Error Correction  
V.42 (LAP-M or MNP 3 & 4) error correction  
Data Compression  
V.42bis, (4:1 throughput) or  
MNP 5 (2:1 throughput) data compression  
Speed Conversion  
Serial port data rates adjustable to 300, 1200,  
2400, 4800, 9600, 19200, 38400, 57600 and  
115200 bps  
79  
 
Appendix B  
Flow Control  
Options  
Xon/Xoff, Hardware RTS/CTS, ENQ/ACK,  
Unix-to-Unix Copy Protocol (UUCP) "Spoofing"  
Mode of Operation  
Full duplex over both dial-up lines and 2-wire  
leased lines; automatic or manual dialing,  
automatic or manual answer  
Intelligent Features  
Fully “AT command” compatible, micro-  
processor controlled remote configuration, EIA  
extended Automode, adaptive line probing,  
automatic symbol rate and carrier frequency  
during start-up, retrain and rate renegotiation,  
autodial, redial, repeat dial, dial linking, pulse or  
tone dial, dial pauses, call status display, auto-  
parity and data rate selection, keyboard-  
controlled modem options, non-volatile memory  
and on-screen displays for modem option  
parameters and up to ten telephone numbers/  
command lines of up to 60 digits each, help  
menus  
Command Buffer  
Modulation  
60 characters  
Trellis Coded Modulation (TCM) at 33600,  
31200, 28800, 26400, 24000, 21600, 19200,  
16800, 14400, 12000 and 9600 bps, Quadrature  
Amplitude Modulation (QAM) at 9600 (non-  
trellis), 4800 and 2400 bps, PSK at 1200 bps,  
FSK at 300 bps  
Fax Modulations  
Fax Carrier  
V.21CH2 FSK at 300 bps  
V.27ter DPSK at 4800 and 2400 bps  
V.29 QAM at 9600 and 7200 bps  
V.17 TCM at 14400, 12000, 9600, and 7200 bps  
V.21CH2 (Half Duplex)  
80  
 
Appendix B  
Frequencies  
1650Hz Mark, 1850Hz Space for Transmit  
Originate; 1650Hz Mark, 1850Hz Space for  
Transmit Answer; V.27ter 1800Hz Originate/  
Answer; V.29 QAM 1700Hz Originate/Answer;  
V.17 TCM 1800Hz Originate/Answer  
Carrier Frequencies  
1800 Hz V.32/V.32bis/V.32terbo/V.34/Enhanced  
V.34--33.6K/31.2K/28.8K/26.4K/24K/21.6K/  
19.2K/16.8K/14.4K/12K/9.6K/7.2K/4.8K  
Carrier Frequencies  
2400 & 1200 bps  
(V.22bis/V.22 or  
Transmit Originate: 1200 Hz  
Transmit Answer: 2400 Hz  
Receive Originate: 2400 Hz  
Receive Answer: 1200 Hz  
Bell 212A Standard)  
Carrier Frequencies,  
300 bps  
(Bell Standard)  
1270 Hz Mark, 1070 Hz Space for Transmit  
Originate; 2225 Hz Mark, 2025 Hz Space for  
Receive Originate; 2225 Hz Mark, 2025 Hz  
Space for Transmit Answer; 1270 Hz Mark,  
1070 Hz Space for Receive Answer  
Carrier Frequencies  
V.21  
980 Hz Mark, 1180 Hz Space for Transmit  
Originate; 1650 Hz Mark, 1850 Hz Space for  
Transmit Answer; 1650 Hz Mark, 1850 Hz  
Space for Receive Originate; 980 Hz Mark, 1180  
Hz Space for Receive Answer  
V.23  
390 Hz Mark, 450 Hz Space for Transmit  
Originate; 1300 Hz Mark, 2100 Hz Space for  
Transmit Answer; 1300 Hz Mark, 2100 Hz  
Space for Receive Originate; 390 Hz Mark, 450  
Hz Space for Receive Answer  
Transmit Level  
-11dBm (dial-up), -15 dBm (leased-line); dBm  
level selectable with DIP-Switch #3 in leased line  
setting  
81  
 
Appendix B  
Frequency Stability  
Receiver Sensitivity  
AGC Dynamic Range  
Interface  
±0.01%  
-43 dBm under worst case conditions  
43 dB  
EIA RS232C/ITU-TSS V.24  
Connectors  
Sixteen DB25 RS232C connectors; sixteen DB9  
connectors for phone line (CC216/916/1432/  
2834 Rack Modem Cabinet) or sixteen RJ11  
connectors for phone line (CC1600 Rack  
Modem Cabinet).  
Diagnostics  
Indicators  
Power-on Self Test, Local Analog Loop, Local  
Digital Loop, Remote Digital Loop.  
LEDs for Transmit Data, Receive Data, Carrier  
Detect, various speed indicators, Off Hook,  
Terminal Ready, Ring Indicator, and Out of  
Service (Busy)  
Controls  
Toggle switch for Out of Service (OOS). On-  
board DIP-Switches and jumpers for various  
modem options.  
Operating  
Temperature  
0° to 50° C (32° to 120° F)  
115 Volts AC, 60Hz, 0.3amp.  
Power  
Requirements  
Power Consumption  
Dimensions  
Approximately 6 watts  
10-1/2" long x 5-1/2" wide  
1.5 pounds  
Weight  
82  
 
Index  
 
Index  
British Telecommunications  
Index  
pic 1-74  
Buffer Length of Command  
Mode...After On-line  
Esca 1-53  
Symbols  
S34 1-53  
Bulletin board systems 1-  
25, 1-32  
Busy Out 1-16  
&E0 1-32  
&E1 1-32  
&E14 1-31, 1-32  
1.1  
Technical Specifica-  
tions 1-81  
C
Callback Attempts 1-52  
Callback Security Com-  
mands 1-45  
Callback Security/Remote  
Configuration Com-  
mands 1-45  
Canadian Limitations Notice 1-  
80  
Card Cage 1-11  
Carrier Detect 1-36  
Carrier Detect Response  
Time 1-51  
A
Abort Timer  
S7 1-51  
AGC Dynamic Range 1-84  
ASCII code 1-26  
AT 1-25  
AT command set 1-41  
AT Commands and S-Register  
Summary 1-57  
AT&T's "call card"  
S9 1-51  
tones 1-34  
Carrier Frequencies 1-83  
Carrier Frequencies (Data) 1-  
83  
Auto-answer 1-26, 1-28  
B
Carrier Loss Disconnect Delay  
Time 1-52  
Backspace Character 1-51  
S5 1-51  
Baud rate  
Serial port 1-29  
Bell/V.21 answer tone selec-  
tion 1-35  
S10 1-52  
Carrier ON 1-19  
Changing Break Time 1-52  
S17 1-52  
Changing Default Param-  
eters 1-28  
British Telecom 1-75  
84  
 
Index  
Clear to Send 1-41  
cleardown on disconnect 1-36  
COM ports  
COM2 1-29  
Command Buffer 1-82  
Command mode characters control 1-37  
Command string 1-26  
Commands  
Attention code 1-25  
Auto-Reliable mode 1-32  
Data compression 1-31, 1-32  
Modem reset 1-25  
Non-Error Correction mode 1-32  
Reliable mode 1-32  
Compatibility 1-81  
Compliance with BABT Requirements 1-73  
CompuServe 1-32  
Configuration Parameters 1-29  
Configuring Software 1-29  
Configuring Your Software 1-25  
Connectors 1-84  
Controls 1-84  
CTS flow control 1-37  
CTS follows RTS 1-41  
CTS signal 1-28  
D
Data Compression 1-31, 1-81  
data compression enabled/disabled 1-37  
Data Format 1-81  
Data Rates 1-81  
Data Rates (fax) 1-81  
Data Rates (modem) 1-81  
Data Set Ready 1-42  
85  
 
Index  
Data Terminal Ready 1-19  
Datacomm software 1-22, 1-  
25, 1-26, 1-29, 1-30, 1-31  
Configuration 1-25, 1-29, 1-  
30  
error correction selection 1-37  
Escape Code Character 1-50  
S2 1-50  
Escape modes selection 1-37  
European Low Voltage Direc-  
tive 1-74  
Diagnostics 1-84  
Dial-Up and Leased Lines 1-18  
Dial-Up Lines 1-18  
Dialing a stored telephone 1-  
40  
Dialing/On-Line/Answering 1-  
22  
Digital Loopback Test (Syn-  
chronous) 1-65  
Digital Loopback Test (Remote/  
Automatic) 1-65  
Digital Loopback Test (Synchro-  
nous Mode) 1-65  
Dimensions 1-84  
DIP Switches and Jumper  
Settings 1-12  
DIP-Switch options 1-14  
DIP-Switch Settings 1-11  
DSR follows CD 1-42  
DTR Control 1-36  
F
factory default values 1-38  
Fax Carrier Frequencies 1-83  
Fax Modulations 1-82  
FCC Regulations for Telephone  
Line Interconnection 1-78  
Features 1-8  
File Transfer Protocols 1-31  
File transfer protocols 1-31  
flash On-Hook 1-44  
FlashPro to Upgrade Modem  
Firmware 1-69  
Flow Control 1-82  
Flow control 1-28  
flow control selection 1-37  
Frequency Stability 1-84  
G
guard tones 1-38  
H
DTR Dialing 1-36  
DTR Dropout Time 1-53  
S25 1-53  
DTR signal 1-28  
Help Screen selection 1-39  
How to Use This Manual 1-9  
E
Enq/Ack pacing 1-37  
Error 1-20  
Error Correction 1-32, 1-81  
Error correction 1-32  
I
In-band Escape Sequence 1-  
45  
86  
 
Index  
Inactivity Timer 1-53  
S30 1-53  
Indicators 1-84  
Initialization strings 1-25, 1-  
28, 1-32  
Macintosh 1-28  
PC-compatible 1-26  
Installation 1-12  
Intelligent Features 1-82  
Interface 1-84  
MNP 5 1-31  
Mode of Operation 1-82  
Model Numbers 1-81  
Modem AT Commands 1-34  
modem baud selection 1-39  
modem ID 1-39  
Modem Initialization Setup 1-  
27  
Modem LED Indicators 1-19  
Modulation 1-82  
Introduction 1-8  
ists operating parameters 1-  
39  
MSD.EXE 1-23  
Multi-Tech command set 1-41  
Multi-Tech responses 1-54  
"Multi-Tech" Result Codes 1-  
55  
K
Kingston Communications (Hull)  
pic 1-74  
N
negotiate V.42 Mode 1-39  
Noise Information 1-39  
Number of Rings Until Modem  
Answers  
L
Lease Line Restoral 1-83  
Limited Warranty 1-67  
Line Feed Character 1-51  
S4 1-51  
S0 1-54  
O
Line Probe 1-37  
Login Password 1-48  
long space “break 1-44  
Loopback Test Enabled 1-43  
Off Hook 1-19  
Off Hook control 1-38  
OOS (Busy Out) Toggle  
Switch 1-16  
Operating Temperature 1-84  
Out of Service 1-17  
M
Macintosh computer 1-23, 1-  
28  
Macintosh Initialization 1-28  
maximum transmit block size  
selection 1-35  
P
Pacing 1-28  
Parameters 1-25, 1-28  
87  
 
Index  
Changing defaults 1-28  
Parity 1-25  
tion 1-30  
reset default values 1-44  
pause during dialing 1-44  
Pause Time for Comma 1-51  
S8 1-51  
PBX/CBX Disconnect Drop  
Time for DSR/CTS/CD 1-  
52  
Result Codes 1-41, 1-44, 1-  
54  
Result codes 1-26  
Result Codes Terse/Verbose  
selection 1-43  
retransmit 1-41  
S24 1-52  
Return Character 1-50  
S3 1-50  
Return character 1-26  
return to Command Mode after  
dialing 1-44  
PC Board Controls 1-13  
PC Initialization Strings 1-26  
Phone Line Connection 1-13  
Power 1-84  
Power Consumption 1-84  
Power Requirements 1-84  
Preliminaries 1-11  
Program V34 Connect  
Speeds 1-54  
Ring Indicator 1-19  
Ringer Equivalence Number 1-  
74  
Rings Which Have Occurred  
S1 1-50  
Protocols 1-31  
RTS signal 1-28  
pulse ratio 1-40  
pulse-dial 1-40  
S
S-Registers 1-50  
S3 1-26  
R
Receive Data 1-19  
Safety Warnings 1-70  
SCC 1-23  
Serial Cable 1-11  
Serial cable 1-28  
Serial port 1-22, 1-23, 1-  
29, 1-31  
serial port commands 1-42  
Serial Port Limitations 1-22  
Service 1-68  
Receiver Sensitivity 1-84  
Recording Modem Informa-  
tion 1-68  
Remote Configuration 1-47  
Remote Configuration Escape  
Character 1-52  
S13 1-52  
Remote Configuration Proce-  
dures 1-47  
Sessions 1-25  
Remote Digital Loopback 1-43  
Remote System Configura-  
Set-up Password 1-48  
Signal Strength Information 1-  
88  
 
Index  
39  
Trellis Coded Modulation  
selection 1-43  
Signal to Noise Ratio Informa-  
tion 1-39  
SIT files 1-31  
U
Speed Conversion 1-81  
speed conversion 1-35  
Standard AT command set  
responses 1-54  
"Standard AT" Result  
Codes 1-56  
UART 1-23  
UARTs 1-22, 1-23, 1-29, 1-  
31, 1-32  
16450 1-22, 1-23, 1-29  
16550 1-22, 1-29  
8250 1-22, 1-23, 1-29  
8250A 1-22, 1-23, 1-29  
Identifying 1-23  
T
Tech Support 1-68  
Technical Specifications 1-81  
Telephone Line 1-11  
Terminal Emulation 1-30  
Terminal emulation 1-30  
Terminal Emulation Setup 1-30  
Upgrading the MT2834BA 1-  
69  
Upgrading the MT2834BL 1-69  
Upgrading the MT2834PCS 1-  
69  
UUCP spoofing 1-42  
TERSE  
55  
VERBOSE 1-  
V
Time Elapse for Escape Se-  
quence 1-53  
S32 1-53  
Time for Carrier  
S7 1-51  
V.25bis Commands 1-48  
V.34 Line Probe 1-36  
V.42 1-32  
V.42bis 1-22, 1-23, 1-29, 1-  
31, 1-32  
Time for Carrier (Abort  
Timer) 1-51  
W
Tone Dialing: Tone Spacing and  
Duration 1-52  
S11 1-52  
Transmission speed 1-23, 1-  
29  
transmit buffer size 1-35  
Transmit Data 1-19  
Transmit Level 1-83  
wait for ringback 1-45  
Wait Time for Dial Tone 1-51  
S6 1-51  
Warranty 1-67  
Weight 1-84  
X
XON/XOFF 1-28  
Xon/Xoff flow control 1-37  
89  
 
S000316  
 

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