ZyXEL Communications 3356P-LAN Non-Volatile Memory, Modem Result Codes, Viewing S Register Values

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.

∙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 and ATWn command lets you choose which set of result codes your modem uses. By default, your modem uses result codes equivalent to the ATX4 and ATW2 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 ATSr=n command to change the value of an S-register r.

For example, to have your modem auto-answer an incoming call after two rings, set S- register 0 to 2. Be sure the n value is between 1 and 255. If n is set to 0, your modem will not answer incoming calls.

Non-Volatile Memory

The Comet has memory set aside for storing user information such as frequently used phone numbers and default command settings. This section covers the topics of storing phone numbers, and saving default settings in the power-on profile.

Storing Phone Numbers

The AT command to store a phone number is in the format AT&Zs=n.

Basic Modem Operation 17