Multi-Tech Systems BA-Series manual Configuring Your Software, Configuring Software for Your Modem

MultiModemBA User Guide

3.1Introduction

Chapter 2 described the installation of PhoneTools, a communications software. If you are using a different software package, there are some points you should take into consideration. 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 MultiModem. The last section of this chapter walks you through the basics of using your modem.

3.2Configuring 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.

3.2.1Configuring 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. 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 MultiModem does not appear on a modem list, you may use the MultiModemII initialization string.

3.4PC Initialization Strings

We recommend the following initialization string for a MultiModem connected to a PC-compatible computer when sharing a line with a telephone:

AT &F X4 S0=0 ^M

This string resets the modem 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 modem and most communications programs. The carriage return character is defined in the modem 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.

The following initialization string is for a MultiModem on a telephone line that functions solely as a

DATA LINE:

AT &F X4 S0= 2 ^M

18