6.	Modem Commands

A modem is controlled by sending it commands.  There are commands to configure a modem and commands  attempt a connection (the dial command).  ZTerm handles the dial command, but you may have to lear bout some commands if you need to do any special configuration of your modem.  This section will eplin some of the most common commands used by ÒHayes compatibleÓ modems.  Advanced modems will haveaddtional commands which are not described here and in many cases will be unique to that brand of mdem. You will need to consult your modem manual for all of its commands and settings.  Some modems ave acommand that will print a summary of its commands.  On US Robotics modems, the commands AT$, A&$, AT$ and ATS$ will give a help summary on a portion of the modem commands.

There are three places in ZTerm where you can enter a modem command.  In the Modem Preferences therere the initialization and deinitialization strings.  These two are to do any modem configuration nedd when ZTerm starts and quits.  And in the Connection settings for each service there is the PreDil nit string.  This is to make any modem configuration changes needed just for this service.  In aditin, you can manually type a modem command in the terminal window.  This is a good way to try out odemcommands or to do one-time changes.

All modem commands start with AT, which is sometimes referred to as modem attention.  You could put veral modem commands together on one line.  In this case, the AT would only be used once, at the beining of the line.  A command is processed by the modem when it receives a RETURN.

Here are some of the more common modem commands:
ATA - answer an incoming call and attempt to connect.
ATDT 5551212 - dial the number using touch tones.
ATDP 5551212 - dial the number using pulse dialing.
ATE1 - turn on the echoing of modem commands.
ATH0 - hang up (go on hook).
ATM0 - speaker always off.
ATM1 - speaker on while dialing until connection established.
ATV1 - verbal result codes (sends ÒCONNECTÓ instead of just Ò1Ó).
ATZ - reset modem to default configuration.
ATS0=1 - set modem to auto answer after one ring. (ThatÕs a zero after the S).
ATS0=0 - turn off auto answer.