Compaq 1592DMT Compaq Armada 1500 Family of Personal Computers Maintenance and - Page 171

Appendix C Modem Commands This appendix contains the modem commands. Your telephony modem must be operated under versions of Microsoft Windows later than 3.1x. The modem will not work under MS-DOS, earlier versions of Microsoft Windows, or Windows NT. Command AT* A/ A Bn Table C-1 Modem Commands Description Attention Code. AT is the command line prefix that tells the modem that a command or sequence of commands is being entered. It precedes all commands except the A/ (repeat) and +++ (escape) commands. Entered alone, AT causes the modem to respond with OK or 0 if it is ready to receive commands. Parameters: none Repeat Last Command. A/ causes the modem to repeat the previous command, such as redialing a telephone number. The previously executed command remains in the command buffer until AT is entered or the power is turned off. Both actions clear the buffer and make the A/ command invalid, since there is no command to repeat. It is not necessary to enter either an AT before or a after this command because they are also held in the command buffer with the previous command. Parameters: none Answer Command. ATA causes the modem to answer a call without waiting for a ring. This is useful in manually answering a call or when making a direct connection with another modem in the originate mode. Parameters: none NOTE: Any command that follows A on the same command line is ignored.The A command is not permitted in some countries. In those cases, ATA returns an error. Communications Standard Option. ATBn determines ITU or Bell standard. Parameters: n = 0 - 3, 15, 16 n = 0 ITU V.22 for 1200 bps n = 1 Bell 212A for 1200 bps (default) n = 2, 3Deselects ITU V.23 reverse channel n = 15 ITU V.21 for 300 bps n = 16 Bell 103J for 300 bps (default) Modem Commands C-1