ZyXEL Communications Comet 336P user manual Modem Result Codes, Viewing S Register Values

AT Command Set/Type

Example

Fax and Voice AT+ commands	AT+FCLASS=2
S-Register command	ATS0=1
S-Register inquiry command	ATS0?

You may browse the lists of available commands for each command set by using the on-line help commands: AT$, AT*$, and AT&$.

Modem Result Codes

When you execute or try to execute an AT command, your modem sends a result code to let you know whether the command was executed. An OK result code means the AT command you sent was executed. If you receive an ERROR code, it means the command was invalid.

The Comet also provides result codes that show:

∙Whether or not a Dial Tone was detected when the modem originated a call.

∙If a busy signal was detected when the modem originated a call.

∙If a remote telephone ring was detected when dialing.

∙The speed, protocol, and error control/data compression method used.

∙If your modem has detected an incoming ring.

Result codes can originate from any of eight result code sets. The ATXn command lets you choose which set of result codes your modem uses. By default, your modem uses result codes equivalent to the ATX5 command.

Viewing S Register Values

Status registers (or "S-registers") contain values that determine the modem’s operating characteristics. Whenever you send an AT command to your modem, you are actually changing the value of an S-register.

You can use the Sr? command to view the value of S-register ‘r’. For example, to view the value of S-register S0, which controls auto-answering, type ATS0? and press Enter. The modem responds with a three-digit character showing the value of this register, followed by OK. A value of 002, for example, means your modem will auto-answer incoming calls after the second ring.

Changing S Register Values

You can use the ATS0=n command to change the value of an S-register.

Basic Modem Operation 13