Compatible Systems 5.4 manual 178

178 Chapter 10 - WAN Link Protocols

All control characters are preceded by a backslash character (\) which tells the router that what follows is an escaped character and should not be literally sent on the WAN interface.

•\r insert a carriage return

•\c don’t add a carriage return to end of line – valid at end of line only

•\x insert a hex digit (range 0 to FF)

•\p pause for 0.3 seconds

•\b send a break character

•\ <space> follow the backslash with a space to insert a space; space char- acters between send or expect commands and the first character of a line are normally stripped

•\t insert a tab

•\n insert a new line

•\q set “quiet mode” – do not log output until another \q encountered

•\\ insert a backslash

A Note About the AT Command Set

Most asynchronous devices (e.g. modems and some terminal adapters) expect AT commands from the router in order to dial or perform other functions. Different modems support different subsets of AT commands. To be certain that the AT commands you are using are correct for your modem, you must refer to the manual that came with your modem.

Every AT command is preceded by “AT,” which tells the modem that the string is destined for it. Listed below are the most common (and commonly supported) AT commands:

•ATDT -- Originate a call by dialing the number sequence which follows this command using tones (note: use a comma in the sequence for a delay)

ϖNote: An asynchronous terminal adapter does not use tones to dial ISDN phone numbers. Use ATD to dial ISDN phone numbers.

•ATH0 -- Hang up (note: the final character is a zero)

•ATM0 -- Set speaker off (note: the final character is a zero)

•ATM1 -- Set speaker on until connect

Modems typically provide a response message depending on the success of an attempted call: