Multi-Tech Systems ISIHP-4U, ISIHP-4SD manual +++ATcr, Force Answer Mode, On Go Back Online

Modem AT Commands & S-Registers

the modem to enter command mode from online mode without disconnecting the call.

+++AT<cr> In-Band Escape Sequence

If the modem is online with a remote modem, you can cause the modem to enter command mode without disconnecting the call by typing an escape code. The default escape code used by the modem is three plus signs (+++)

followed by the letters AT, up to 10 command characters (most typically H, to hang up), and ENTER. The modem then escapes to command mode, executes the command (if any), and remains in command mode. For example, to hang up the modem at the end of a call, type +++ATH <cr>.

AForce Answer Mode

You can use the A command to force the modem into answer mode. Type ATA when in command mode to immediately bring your modem off-hook, out of command mode, into online answer mode, and to cause it to transmit its carrier signal over the phone line. If no responding carrier tone is received by your modem within 45 seconds (or by the time you specified in register S7), your modem stops transmitting its tone, hangs up, and goes back into command mode.

On Go Back Online

n = 0, 1, or 3 Default: none

Use the O command to bring the modem out of command mode and back into online mode. The O command reverses the result of entering the escape code. The O command brings modem into the online mode (originate or answer) it was in prior to entering command mode.

O0 causes the modem to exit command mode and return to online data mode.

O1 causes the modem to issue a retrain before returning to online data mode.

O3 causes the modem to issue a rate renegotiation before returning to online data mode.

MultiModemISI Hybrid Series, ISIHP-2S/2U/4S/4U/4SD 93