Multi-Tech MultiModem ISIHI-2S, Manual

Page: 69 / 186

MultiModemISI Hybrid Series, ISIHI-2S 69
Chapter 4—MODEM AT Commands, S-Registers, Result Codes
Modem
; Return to Command Mode After Dialing
Enter a semicolon (;) as the last character of a dialing command to cause the modem to
return to command mode immediately after executing the command instead of waiting for
a carrier signal and going online.
For example, type ATDT5551212; to tone-dial the number and immediately go back into
command mode. The semicolon is useful when modem data transfer is not desired, as in
voice communications, or in applications using touch tones as a data entry method, such
as bank-by-phone.
! Flash On-Hook
Some switchboard systems react to a momentary on-hook condition. Insert an
exclamation mark into the dialing command to cause the modem to “flash” on-hook for
half a second, just as if you had pressed the switch hook on a telephone set for half a
second. (With U.K. models, the exclamation mark causes the modem to flash on-hook for
90 milliseconds.)
For example, to flash on-hook to transfer to extension 5678 after dialing the number 555-
1234, type ATDT5551234,,!5678. The commas cause a 4-second pause.
$ Detect Call Card Tone
Use the $ command to dial services that require you to enter your call card number after
a tone. The $ character in the dialing string causes the modem to pause and wait for an
AT&T call card
bong or a 1600 Hz tone. When the modem detects the tone, it processes
the rest of the dialing string. If it does not detect the tone within the time set in register
S7, the modem stops processing the dial string with a NO CARRIER message. Pressing
any key also terminates the $ command.
@ Quiet Answer
Use the @ command to access a system that does not provide a dial tone. The @
command causes the modem to wait before processing the next character in the dialing
string. The wait is for one or more rings back followed by five seconds of silence.
For example, ATDT5551212@6313550 causes the modem to dial the first number (555-
1212), then wait for the time specified in register S7 for at least one ringback and five
seconds of silence. If the modem detects a busy signal, it hangs up and generates a
BUSY
result code. If it does not detect five seconds of silence, it hangs up and generates
a NO ANSWER result code. If it does detect five seconds of silence, it dials the second
number (631-3550).
^ Disable Data Calling Tone Transmission
Use the ^ command to disable the transmission of data calling tones. In the following
example, the ^ command is used to tone dial 555-1212 and suppress data calling tone
transmission. ATDT^5551212