Multi-Tech Systems MT5600ZDX User Manual

Owners Manual

Model MT5600ZDX

NOTE: This equipment has been tested and found to comply with the limits for a

Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are

designed to provide reasonable protection against harmful interference when

the equipment is operated in a residential installation. This equipment generates,

uses and can radiate radio frequency energy, and if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur

in a particular installation. If this equipment does cause harmful interference to

radio or television reception, which can be determined by turning the equipment

off and on, the user is encouraged to try to correct the interference by one or

more of the following measures:

Reorient or relocate the receiving antenna. Increase the separation between the equipment and receiver. Increase the separation between the equipment and receiver. Connect the equipment into an outlet on a circuit different

from that of which the receiver is connected. Consult the dealer or an experienced radio/TV technician for help. WARNING: Changes or modifications to this unit not expressly approved by the

party responsible for compliance could void the users authority to operate this equipment. The Telephone Consumer Protection Act of 1991 makes it unlawful for any person

to use a computer or other electronic device to send any message via a telephone fax machine unless such message clearly contains in a margin at the top or bottom of each page or the first page of the transmission, the date and time it is sent and an identification of the business or other entity, or other individual sending the message and the telephone number of the sending machine or such business, other entity, or individual. See the cover page of your fax software manual for setup details. This device complies with Part 15 of the FCC rules. Operation is

subject to the following conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

Owners Manual

82068601 Revision B

Model MT5600ZDX

This publication may not be reproduced, in whole or in part, without prior expressed written

Multi-Tech Systems, Inc. makes no representations or warranties with respect to the contents

hereof and specifically disclaims any implied warranties of merchantability or fitness for any

particular purpose. Furthermore, Multi-Tech Systems, Inc. reserves the right to revise this

publication and to make changes from time to time in the content hereof without obligation of

Multi-Tech Systems, Inc. to notify any person or organization of such revisions or changes.

Revision Date Description

A 7/14/97 Manual released at Revision A.

B 9/15/98 Added #V, Class 2 fax, and V.90 information.

MultiModemZDX, Multi-Tech, and the Multi-Tech logo are trademarks of Multi-Tech Systems,

Inc. K56flex is a registered trademark of Rockwell and Lucent Technologies Corp.

sion. All brand and product names mentioned in this publication are trademarks or

registered trademarks of their respective companies.

Multi-Tech Systems, Inc.

2205 Woodale Drive

Mounds View, Minnesota 55112 U.S.A.

(612) 785-3500 or (800) 328-9717

U. S. FAX 612-785-9874

Fax-Back Service 612-717-5888

Technical Support (800) 972-2439 BBS (612) 785-3702 or (800) 392-2432 Internet Address: http://www.multitech.com

Technical Writer: jeff@multitech.com

Model MT5600ZDX

Contents

Chapter 1

Introduction ................................................... 6

Product Description ....................................... 6

What Is in Your Modem Package?................8

Chapter 2

Installation .....................................................8

Computer ........................................................9

Serial Cable ................................................... 9

Telephone Line ...............................................9

Safety Warnings ............................................. 9

Communications Software ..........................10

Assemble the Modem ...................................10

Installation Process ..................................... 11

LED Indicators ............................................13

Is Your MultiModemZDX Ready for Use? ..15

Operating Your MultiModemZDX ..............15

Simple Operations ....................................... 16

Software Configuration ............................... 17

Hardware/Software Confirmation ..............18

Troubleshooting .......................................... 18

Chapter 3

AT Commands ..............................................25

S-Registers ................................................... 44

Result Codes ................................................ 56

Chapter 4

Local Analog Loopback Test/V.54 Loop 3 .60

Digital Loopback Test/V.54 Loop 2 ............61

Chapter 5

Introduction .................................................64

Limited Warranty ......................................... 64

Tech Support ................................................ 64

Recording Modem Information .................. 65

Service ..........................................................65

About the Multi-Tech BBS .......................... 66

Logging on to the Multi-Tech BBS .............66

Downloading a File ..................................... 66

Reading a Message ......................................68

Leaving a Message ...................................... 68

Bulletins .......................................................68

Using Flash to Upgrade Firmware .............68

About CompuServe/Internet ........................ 70

About the Multi-Tech Fax-Back Service ....70

Owners Manual

Appendix A - Technical Specifications ......................... 71

Appendix B - Regulatory Information .......................... 76

Appendix C - V.90 Information..................................... 82

Model MT5600ZDX

Introduction

Welcome to the world of data communications. You have acquired one of the finest intelligent data/fax modems available today, the MultiModemZDX, from Multi-Tech Systems. This Owners Manual will help you install, configure, test and use your MultiModemZDX.

Product Description

Your MultiModemZDX incorporates new modem technologies called V.90 and K56flexTM, that enable Internet connections at data rates up to 56K bps over standard telephone lines. This 56K technology is able to propel data downstream from the Internet to your computer at speeds of up to 56K bps because data is digitally encoded instead of modulated. Upstream transmission, mostly keystroke and mouse commands from your computer to the central site, continue to flow at the conventional data rate of 33.6K bps.

Your MultiModemZDX offers interactive automatic dialing, as well as command mode option configuration. You may store four command line/ telephone numbers, of up to 40 characters each, in the modems nonvolatile memory. The modem pulse or tone dials, and recognizes dial tones and busy signals for reliable call-progress detection. The modem can detect AT&T calling card tones. It is FCC-Registered for connection to telephone networks without any Data Access Arrangements (DAAs).

Though this modem is capable of 56K bps download performance line impairments, public

telephone infrastructure and other external technological factors currently prevent maximum 56K bps connections.

The MultiModemZDX is a desktop fax/modem for compatible IBM Personal Computers; and provides dial-up asynchronous communication capability with other personal computers, terminals, on-line computer services or other types of computer systems.

Connection to the phone line and/or an attached telephone device is made by RJ11 modular type connectors; the PC connection is made via an RS232C/V.24 serial cable receptacle; and low voltage DC power is supplied to the MultiModemZDX through a modular power supply connection included with the modem. All these connections are located on the rear of the MultiModemZDX. Hardware installation procedures are described in Chapter 2.

Owners Manual

General features include: 4 Compliance with major ITU-T, TIA, and EIA international standards to

ensure compatibility with other modems.

4 Distinguishes data, and fax calls. 4 Caller ID to identify your callers phone number (available on U.S.

products).

Data

4 Supports V.90 and K56flexTM for data transmission speeds up to 56Kbps,

while maintaining compatibility with lower-speed modems. Note the V.90 and K56flex standards asymmetrically transfers data--

client downloads at speeds up to 56K bps, client uploads at speeds up to 33.6K bps.

4 Supports the enhanced ITU-T V.34 standard, with data transmission

speeds to 33.6K bps, while also maintaining compatibility with lowerspeed modems.

4 Supports V.90 and K56flex speeds plus 33.6K, 31.2K, 28.8K, 26.4K,

24K, 21.6K, 19.2K, 16.8K, 14.4K, 12K, 9.6K, 7.2K, 4.8K, 2.4K, 1.2K, and 0-300 bps.

4 Automatic fallback to slower speeds in noisy line conditions, and fall-

forward to faster speeds as conditions improve (line quality monitoring).

4 ITU V.42 LAP-M and MNP Class 3 and 4 error correction. 4 ITU V.42bis (4-to-1) and MNP 5 (2-to-1) data compression. 4 MNP10 and MNP10EC

tion).

4 H.324 compliant (videophone ready). 4 Automatic disabling of compression when transferring already-com-

pressed files.

4 Autodial, redial, pulse (rotary) and touch-tone dial. 4 Dial tone and busy signal detection for reliable call-progress detection. 4 Distinctive ring support to route voice, data, or fax calls on a single

phone line.

4 Plug and Play (PnP) serial support. 4 FlashROM upgradable. 4 Compatibility with the standard AT command set used by most commu-

nication programs.

Enhanced Cellular Performance (error correc-

Model MT5600ZDX

Fax

4 Supports V.17, Class 1and Class 2 Group 3 fax communication

standards, allowing it to communicate with other fax modems as well as with fax machines.

4 Sends and receives faxes from your computer at 14,400 bps, 9600 bps,

7200 bps, 4800 bps, 2400 bps, or 300 bps.

What Is in Your Modem Package?

Your MultiModemZDX has several components. Make sure you have them all before installing your modem. Your package should include:

 MultiModemZDX data/fax modem  DC power supply  One set of four plastic feet  Two sets of Velcro fasteners  Telephone cord  MultiModemZDX Owners Manual  Data Communications Software  One Set-Up diskette  Brochure with warranty registration card

If any of these items are missing, please contact Multi-Tech Systems or your dealer/distributor.

Installation

In addition to the contents of the MultiModemZDX package, you will need the following equipment.

Computer

The MultiModemZDX can be connected to any computer with an RS-232 serial port.

Owners Manual

Serial Cable

You must provide a serial cable to connect the MultiModemZDX to your computer. Serial cables are available at computer stores and many office supply stores. The cable must have a DB-25P connector at the modem end. For IBM and compatible computers, the other end may have a DB-25P connector or a DB-9S connector, depending on your particular computer and whether you are using the COM1 or the COM2 serial port. The FCC requires cables to be shielded.

DB-25

DB-9

Telephone Line

You must have a telephone line with a conveniently located connector (jack) to accept the cable that comes with the MultiModemZDX. If you do not have a telephone jack near your computer, you should install an extension before proceeding. In North America, telephone extension kits and accessories are available at electronics stores and wherever telephones are sold. You may also hire an independent contractor or your local telephone company to do the work. If you want to add a line for your MultiModemZDX fax modem, you must contact your telephone company.

Model MT5600ZDX

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.

Communications Software

To operate the ZDX, you must have data and fax communications software. Data comm software simplifies control of the modem by guiding you through the process of selecting your serial port, your port speed, and other variables, and then storing your settings, including frequently called phone numbers, so they can be recalled with the stroke of a key or the click of a mouse. The software must be set up, or configured, before you can use it. You must have Microsoft Windows 3.1 or later to run most prevalent software packages. If you require software for DOS or for the Macintosh operating systems, please contact Multi-Tech Sales.

Assemble the Modem

The only assembly required is to mount the feet on the bottom of the modem. Simply peel the four self-adhesive plastic feet off the backing strip and press them into the recesses on the bottom of the modem. Alternately, or additionally, you can use the self-adhesive Velcro patches to mount the modem to a vertical surface or to keep it from being dislodged on a horizontal surface. If you use the Velcro patches, we recommend that you mount them where they will not obscure the labels on the bottom of the modem. The ZDX has no special placement restrictions, but we recommend that you place it where you can see the indicators on the front panel.

Owners Manual

Installation Process

The installation of the MultiModemZDX consists of making the physical connections necessary to render the modem functional with your computer. This includes making the proper serial, phone line, and power connections.

POWER

Power Connector (to Transformer)

RS232

DB25 to Computer

PHONE LINE

RJ11/Phone Connection

RJ11/PSTN Connection

Figure 2-2. MultiModemZDX Connections

To install your MultiModemZDX:

1. Attach MultiModemZDX to dial-up phone lines using the RJ11 telephone cord. This is accomplished by plugging one end of the cable provided with the MultiModemZDX into the telephone jack in your home or office; and plugging the other end into the LINE jack on the MultiModemZDX.

NOTE

The LINE jack is not interchangeable with the PHONE jack on the MultiModemZDX. Do not plug the telephone into the LINE jack or the line cable into the PHONE jack. BABT regulations require that the telecommunication cable be connected to the modem prior to being connected to the network.

2. Attach your MultiModemZDX to your PC or terminal with an RS232 (or V.24) cable (see Figure 2-1 and Figure 2-2). Be sure to tighten the mounting screws on the DB connectors.

3. Connect your telephone set to phone jack via RJ11 cable.

4. Attach your MultiModemZDX to the AC Power transformer and plugging the AC connector into a live AC outlet.

NOTE

Use only the power supply provided with the MultiModemZDX. Use of any other power supply will void the warranty and could damage the modem.

Model MT5600ZDX

5. Turn on power by flipping the "ON/OFF" switch on the side of the MultiModemZDX to the "ON" position.

6. Make sure modem and computer/terminal serial port baud rates are adjusted. (Note that several programs can check this for you. If you have MS-DOS 5.0 or higher, a program called MSD.EXE [Microsoft Diagnostics] is in your DOS directory. Typing MSD at the DOS prompt brings up a screen that provides a variety of information about your computer. Select COM ports and it lists information about your com port, e.g., UART Type, Address, and IRQ, to name a few. Once you know your serial port's UART type, you can set your communications's software appropriately.)

7. Proceed to Chapter 3 of this manual, or to your data communications

software manual.

✳

Figure 2-2a. MultiModemZDX Connections

LED Indicators

The MultiModemZDX has ten LED indicators to report MultiModemZDX status (such as verifying proper installation) and line activity (such as monitoring the status of a connection).

Owners Manual

Figure 2-3. MultiModemZDX Front Panel

Transmit Data. The TD LED flashes when data is being transmitted (on for a space, off for a mark). Signals on this circuit are generated by the terminal and transferred to the transmitter of the MultiModemZDX. The transmitting terminal should hold this line in the marking state when no data is being transmitted, including intervals between characters or words. The TRANSMIT (TD) LED indicates the status of this circuit.

Receive Data. The RD LED flashes when data is being received (on for a space, off for a mark). Data signals received from the remote MultiModemZDX are presented on this line. The RECEIVE (RD) LED indicates the status of this signal.

Carrier Detect. This LED lights when a valid carrier signal from another modem is detected.

V.90 or K56flex. This LED is lit when connected to an ISP-type K56flex server. The actual connection speed is contingent upon server capabilities and line conditions.

Model MT5600ZDX

V.34. This LED is lit when the modem is connected in V.34 mode.

V.32bis. This LED is lit when the modem is connected in V.32bis mode. Note at speeds lower than a V.32bis connection, the MultiModemZDX speed LEDs remain unlit.

Off Hook. The condition of Off Hook indicates to the central office that the MultiModemZDX wants the phone line to do something (i.e., dial or answer a call). This LED is also lit when the MultiModemZDX has achieved on-line status.

Terminal Ready. When TR is lit, the MultiModemZDX can answer an incoming call. This signal (TR or DTR) provides a means for the terminal or computer to control the MultiModemZDX's connection to the communications channel. A high DTR signal is required by the MultiModemZDX to be able to communicate. The state of the TR LED matches that of the DTR circuit on pin 20 of the RS232/V.24 interface.

Error Correction. This LED is lit when the modem is set for V.42 error correction, and flashes on and off when data compression is activated.

Fax. This LED is lit when the modem is connected in Fax mode.

Owners Manual

Is Your MultiModemZDX Ready for Use?

As soon as you have connected power to the modem, if youre an experienced modem user, you may simply want to check your modems settings for data compression, error correction, and so on. You may find that you can get moving quite quickly if you just issue the AT&V<cr> command. This command lists how your modem is currently configured, the stored (user) profiles, and the first four stored telephone numbers. If you come across a setting youre unsure of, refer to Chapter 3 of this manual for AT command and S-Register explanations and defaults. If youre a novice, please continue to the next sections of this chapter.

Operating Your MultiModemZDX

You control your MultiModemZDX by issuing AT commands and setting S-Registers. Right now your MultiModemZDX is set up for the most typical user application, that is, as a traditional modem set to make a dial-up call to a remote installation where the call is answered automatically; therefore, you shouldnt need to change the current default configuration. (If however, you know that your application does not follow this profile, please refer to Chapter 3 for AT Commands and S-Registers.)

In operating your MultiModemZDX it is likely that you will use your data communications software to either:

· enter terminal mode, where you can speak most directly to the modem

by issuing AT commands, or to

· launch a datacomm session through a set of modem configurations which

you select and then associate with a target telephone number. Once you have created, saved, and named this set of information according to your connection needs and your datacomm softwares conventions, the software then simplifies your dialing because you neednt reconfigure your modem, nor run the risk of mistakenly keying-in incorrect information.

Either way, you need to understand that an AT command is the method by which your modem is controlled, and must therefore prefix nearly all commands. AT stands for attention, and alerts the modem that a command follows. You may enter these commands with either upper- or lower-case characters. Entering AT automatically sets the modems serial baud rate to match your computers and also sets the modems parity. It also clears the

Model MT5600ZDX

modems command buffer. Once youre in terminal mode, enter AT followed by <CR> to check whether your modem is operational. If everythings fine, your modem will respond OK.

Simple Operations

You can dial by using the ATD command and the phone number of the modem with which you wish to connect, e.g., ATD6127853500. Your modem will dial the number; a scrambling noise is heard as the modem negotiates the kind of connection it can make, and once the modems have settled on a common connection, a connect message on your computers video is displayed. To hang up a call, enter ATH0<CR>. Your modem will return on hook, just as if you had returned a phones handset to its cradle. Your video now displays OK, signifying that your modem is ready for your next command.

Software Configuration

Communications software must be configured to work with the MultiModemZDX, your computer, and the remote system it is calling. Fortunately, most communications programs make the process easy by providing a default initialization string to your modem as well as defaults for most of the other required parameters.

Some software programs allow you to select your modem type from a menu. By this method, initialization strings that correspond to a particular modem type can be selected to operate optimally with the software in use.

*: Refer to your respective software manual for further information on your communications software.

Owners Manual

Figure 2-5. MultiModemZDX Initialization Setup

Other software programs require you enter an initialization string in the software modem setup screen. If this is the requirement in your software application, enter the following command string to initialize your modem: AT&F<cr>. This setting configures your modem to operate optimally with the software it is utilizing.

Hardware/Software Confirmation

To confirm that your modem (hardware) and communications package (software) is working properly:

1. Go into terminal mode in your communications package.

2. To determine if your computer and modem are communicating properly, Enter: AT<CR> At this point your video monitor should display OK. If the characters you typed do not appear or if double characters appear, see the troubleshooting section of this chapter.

3. To confirm how your MultiModemZDX is configured, enter AT&V<cr>. The current MultiModemZDX configuration is displayed as show below.

Example: AT&V ACTIVE PROFILE: B0 E1 L1 M1 N1 QO T V1 W0 X4 Y0 &C0 &D0 &G2 &J0 &K3 &Q5 &R1 &S0 &T4 &X0 &Y0 S00:002 S01:000 S02:043 S03:013 S04:010 S05:008 S06:002 S07:030 S08:002 S09:006 S10:014 S11:255 S12:050 S18:000 S25:005 S26:001 S36:007 S37:000 S38:020 S46:138 S48:007 S95:000

Model MT5600ZDX

Troubleshooting

Your MultiModemZDX was thoroughly tested at the factory before it was shipped. If you are unable to make a successful connection or if you experience data loss or garbled characters during your connection, it is possible that the modem is defective. However, it is more likely that the source of your problem lies elsewhere. Problems you may encounter include:

 None of the LEDs light when the modem is on;  The modem does not respond to commands;  The modem dials but is unable to make a connection;  The modem disconnects while online;  The modem cannot connect when answering;  Slow file transfer;  Losing data;or  Garbage characters on the monitor

None of the LEDs Light When the Modem Is On

When you turn on the MultiModemZDX, the LED indicators on the front panel should flash briefly as the modem runs a self-test. If the LEDs remain off, the modem is probably not receiving power.

4 Make sure the modems power switch is on, especially if you normally turn on the

modem by turning on a power strip.

4 If the power supply is plugged into a power strip, make sure the power strip is

plugged in, and its power switch is on.

4 Make sure the power supply module is firmly connected to the modem and to the

wall outlet or power strip.

4 If the power strip is on and the modem switch is on, try moving the modem power

supply to another outlet on the power strip.

4 Test the outlet is live by plugging a lamp into it. 4 The modem or power supply may be defective. If you have another Multi-Tech

modem, try swapping modems. If the problem goes away, the first modem or power supply may be defective. Call Tech Support for assistance.

*: Do not under any circumstances replace the power supply module with one designed for another product, as it may damage the modem and void your warranty.

The Modem Does Not Respond to Commands

4 Make sure the modem is plugged in and turned on. (See None of the LEDs Light

When the Modem Is On.)

Owners Manual

4 Make sure you are issuing the modem commands from the data communications

software, either manually in terminal mode or automatically once you have configured the software. (You cannot send commands to the modem from the DOS prompt.)

4 Make sure you are in terminal mode in your data communications program, then

type AT and press ENTER. If you get an OK response, your connections are good and the problem likely is in your phonebook entry or session settings. Be sure your modem is not in data mode when you type a command. Use the escape character sequence to switch to terminal mode. The default escape sequence must wait at least one second, enter +++, and pause another second or more before entering a command.

4 The E0 and Q1 commands may be in effect, disabling echo and responses. Verify

this with the &V command. To enable echo and responses, enter ATE1Q0<cr>.

4 Try resetting your modem by turning it off and on. Make sure there is a reset

command (&F) in your initialization string, or your modem may not initialize correctly.

4 If you dont get an OK, the problem may still be in the communications software.

Make sure you have done whatever is necessary in your software to make a port connection. Not all communications programs connect to the COM port automatically. Some connect when the software loads and remain connected until the program terminates. Others can disconnect without exiting the program. Many communications software packages also allow multiple terminals to be open, but only one can access the modem at a time. If your package reports that it cannot make a connection, yet the modems TR indicator is on, click on the Window menu to see if more than one terminal is open. The modems TR indicator shows that the software has made a connection with the modem through the COM port.

4 Your communications software settings may not match the physical port the

modem is connected to. The serial cable may be plugged into the wrong connectorcheck your computer documentation to make sure. Or you may have selected a COM port in your software other than the one the modem is physically connected tocompare the settings in your software to the physical connection.

4 If the modem is on, the cable is plugged into the correct port, the communications

software is configured correctly, and you still dont get an OK, the fault may be in the serial cable. Make sure it is firmly connected at both ends.

4 Is this the first time you have used the cable? If so, it may not be correct. Check

the cable description on the packaging to make sure the cable is the right one for your computer.

4 Peripheral expansion cards, such as bus mouse and sound cards, may include a

serial port preconfigured as COM1 or COM2. The extra serial port, or the card itself, may use the same COM port, memory address, or interrupt request (IRQ) as your communications port. Be sure to disable any unused ports.

To look for address or IRQ conflicts if you use Windows 3.1x, select File, Run in Program Manager, type MSD, and press ENTER. Then select Mouse, COM Ports, and IRQ Status and note the addresses and IRQs that are in use. If you find an IRQ conflict, note which IRQs are not being used, then change one of the

Model MT5600ZDX

conflicting devices to use one of the unused IRQs. If you find an address conflict, change the address of one of the conflicting devices.

To change a port address or IRQ in Windows 3.1x, double-click the Control Panel icon, then the Ports icon. Click on the port you want to change, click Settings, click Advanced, and select the new port address and/or interrupt. If you wish to use COM3 or COM4, note that COM3 shares an IRQ with COM1, as does COM4 with COM2, so you should change their IRQs to unused ones, if possible.

If you use Windows 95, right-click on My Computer, select Properties from the menu, click on the Device Manager tab, double-click on Ports, then double-click on the Communications Port your modem is connected to. In the ports Properties sheet, click on the Resources tab to see the ports Input/Output range and Interrupt Request. If another device is using the same address range or IRQ, it will appear in the Conflicting Device List. Uncheck Use Automatic Settings to change the ports settings so they do not conflict with the other device, or select the port the conflicting device is on and change it instead. If you need to open your computer to change switches or jumpers on the conflicting device; refer to the devices documentation.

4 The serial port may be defective. If you have another serial port, install the

modem on it, change the COM port setting in your software, and try again.

4 The modem may be defective. If you have another Multi-Tech modem, try

swapping modems. If the problem goes away, the first modem is possibly defective. Call Tech Support for assistance (see Chapter 5).

The Modem Dials But Cannot Make a Connection

There can be several reasons the MultiModemZDX fails to make a connection. Possibilities include

 modem is not configured properly.  lack of a physical connection to the telephone line.  a wrong dial tone.  a busy signal.  a wrong number.  no modem at the other end.  a faulty modem, computer, or software at the other end.  incompatibility between modems.

You can narrow the list of possibilities by using extended result codes. To enable them, enter ATV1X4 and press ENTER while in terminal mode, or include V1X4 in the modems initialization string. When you dial again, the modem will report the calls progress.

Both local and remote modems may be misconfigured, thus encumbering the

negotiation process between modems. The solution may be to modify modem parameters via AT command strings. There are other configurations you can

Owners Manual

modify as well. Note that you can return to the modem's default configuration by entering AT&F.

If your application requires modification, use the command strings shown below corresponding to your application:

4 If the modem reports NO DIALTONE, check that the modems telephone line cable

is connected to both the modems LINE jack (not the PHONE jack) and the telephone wall jack. If the cable looks secure, try replacing it. If that doesnt work, the problem may be in your buildings telephone installation. To test the building installation, plug a telephone into your modems telephone wall jack and listen for a dial tone. If you hear a dial tone, your modem may be installed behind a company phone system (PBX) with an internal dial tone that sounds different from the normal dial tone. In that case, the modem may not recognize the dial tone and may treat it as an error. Check your PBX manual to see if you can change the

Model MT5600ZDX

internal dial tone; if you cant, change your modems initialization string to replace X4 with X3, which will cause the modem to ignore dial tones.

4 If the modem reports BUSY, the other number may be busy, in which case you

should try again later, or it may indicate that you have failed to add a 9, prefix to the phone number if you must dial 9 for an outside line.

If you must dial 9 to get an outside line, the easiest way to dial it automatically is to include it in the modems dial prefix, e.g., ATDT9,. Note the comma, which inserts a pause before the number is dialed. By inserting 9, into the dial prefix, you do not have to include it in each directory entry.

To change the dial prefix in your communications package, select Setup, Modem; then select the modem type you are using, and type the new prefix in the Dial Prefix box. To change the dial prefix in Windows Terminal, select Settings, Modem Commands. To change it in Windows 95 HyperTerminal, select Call, Connect from the menu bar, click Dialing Properties, and type 9 in the local and long distance boxes in How I Dial from This Location.

4 If the modem reports NO ANSWER, the other system has failed to go off-hook,

or you might have dialed a wrong number. Check the number.

4 If the modem reports NO CARRIER, the phone was answered at the other end,

but no connection was made. You might have dialed a wrong number, and a person answered instead of a computer, or you might have dialed the correct number but the other computer or software was turned off or faulty. Check the number and try again, or try calling another system to make sure your modem is working. Also, try calling the number on your telephone. If you hear harsh sounds, then another modem is answering the call, and the modems may be having problems negotiating because of modem incompatibilities or line noise. Try connecting at a lower speed.

The Modem Disconnects While Online

4 If you have call waiting on the same phone line as your modem, it may interrupt

your connection when someone tries to call you. If you have call waiting, disable it before each call. In most telephone areas, you can disable call waiting by preceding the telephone number with *70 (check with your local telephone company).

You can automatically disable call waiting by including the disabling code in the modems dial prefix (e.g., ATDT*70,note the comma, which inserts a pause before the number is dialed). To change the dial prefix in your communications package, select Setup, Modem; then select the modem type you are using, and type the new prefix in the Dial Prefix box. To change the dial prefix in Windows Terminal, select Settings, Modem Commands. To change it in Windows 95 HyperTerminal, select Call, Connect from the menu bar, click Dialing Properties, check This Location has Call Waiting, and select the correct code for your phone service.

Owners Manual

4 If you have extension phones on the same line as your modem, you or someone

else can interrupt the connection by picking up another phone. If this is a frequent problem, disconnect the extension phones before using the modem, or install another phone line especially for the modem.

4 Check for loose connections between the modem and the computer, the

telephone jack, and AC power.

4 You may have had a poor connection because of line conditions or the problem

may have originated on the other end of the line. Try again.

4 If you were online with a BBS, it may have hung up on you because of lack of

activity on your part or because you exceeded your time limit for the day. Try again.

The Modem Cannot Connect When Answering

4 Auto-answer may be disabled. Turn on auto-answer in your datacomm program

or send the command ATS0=1 to your modem in terminal mode.

Slow File Transfer

4 You may have an older UART. For best throughput, install a 16550AFN UART or

a Multi-Tech ISI serial port card.

4 If you are running under Windows 3.1 and have a 16550AFN UART, you must

replace the Windows serial driver, COMM.DRV, to take full advantage of the UARTs speed.

4 If you are using a slow transfer protocol, such as Xmodem or Kermit, try Zmodem

or Ymodem/G instead.

4 Is your line noisy? If there is static on your line, the modem has to resend many

blocks of data to insure accuracy. You must have a clean line for maximum speed.

4 Are you downloading a compressed file with MNP 5 hardware compression

enabled? Since hardware data compression cannot compress a file already compressed by an archiving program, the transfer can be marginally slower with data compression enabled than with it disabled.

4 Try entering the &V (View Parameters) command, making a screen print of the

diagnostics listing, and checking for parameters that may be unacceptable.

Losing Data

4 If you are using data compression and a high speed serial port, set the serial port

baud rate to four times the data rate.

4 Your UART may not be reliable at serial port speeds over 9600 bps or 19,200 bps.

Turn off data compression, reset your serial port speed to a lower rate, or replace your serial port with a faster one.

Model MT5600ZDX

4 Make sure the flow control method you selected in software matches the method

selected in the modem.

4 If you are running under Windows 3.1 and have a 16550AFN UART, you may need

to turn on the 16550s data buffers and/or replace the Windows serial driver, COMM.DRV.

4 Try entering the &V (View Parameters) command, making a screen print of the

diagnostics listing, and checking for parameters that may be unacceptable.

Garbage Characters on the Monitor

4 Your computer and the remote computer may be set to different word lengths,

stop bits, or parities. If you have connected at 8-N-1, try changing to 7-E-1, or vice-versa, using your communications software.

4 You may be experiencing line noise. Enable error correction, if it is disabled, or

hang up and call again; you may get a better connection.

4 At speeds above 2400 bps, the remote modem might not use the same

transmission or error correction standards as your modem. Try connecting at a slower speed or disabling error correction. (With no error correction, however, line noise can cause garbage characters.)

4 Try entering the &V (View Parameters) command, making a screen print of the

diagnostics listing, and checking for parameters that may be unacceptable.

Owners Manual

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 is a summary and of the AT commands recognized by the MT5600ZDX.

Command: AT Attention Code

Values: n/a Description: The attention code precedes all command lines

except A/ and the escape sequence.

Command: ENTER or Carriage Return <CR> Key

Values: n/a Description: Press the ENTER or Carriage Return key to execute

most commands.

Command: $ Detect AT&T's "call card" tone

Values: 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 when originating an on-line connection--

Command: A Answer

Values: n/a Description: Answer an incoming call before the final ring.

Command: A/ Repeat Last Command

Values: n/a Description: Repeat the last command string. Do not precede this

command with AT. Do not press ENTER to execute.

Model MT5600ZDX

Command: Bn Communication Standard Setting

Values: n = 0 or 1 Default: 0 and 1 Description: B0 Select ITU-T V.22 mode when modem is at 1200 bps.

B1 Select Bell 212A when modem is at 1200 bps.

Command: Ds Dial

Values: s = dial string (phone number and dial modifiers) Default: none Description: Dial telephone number s, where s may up to 40

characters. Dial string modifiers:

0-9 DTMF digits 0 to 9 * The "star" digit (tone dialing only) # The "gate" digit (tone dialing only) A-D A, B, C, and D DTMF digits. Country specific;

some countries may prohibit these digits.

L Redial last number. (Must be placed immediately

after ATD.)

P Pulse-dial following numbers in command. T Tone-dial following numbers in command V Switch to speakerphone mode and dial the fol-

lowing number. Use ATH command to hang up.

W Wait for a new dial tone before continuing to dial.

(X0, X1, X3, or X4 must be selected.)

S Dial a telephone number previously stored using

the &Zn=x command (see &Zn=x command for further information). The range of n is 0-3.

, Pause during dialing for time set in register S8. ; Return to command mode after dialing. (Place at

end of dial string.)

! Hook flash. Causes the modem to go on-hook for

one-half second, then off-hook again (time specified in S29).

@ Wait for quiet answer. Causes modem to wait for

a ringback, then 5 seconds of silence, before processing next part of command. If silence is not detected, the modem returns a NO ANSWER code.

$ Wait for credit card dialing tone before continuing

with the dial string (wait contingent on S7 setting).

^ Toggles data calling tone enable/disable: applica-

ble to current dial attempt.

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