Changing S Register Values; Non-Volatile Memory - ZyXEL Communications U-336S User Manual

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.
Some S-registers are bit mapped. For these registers, you can use the
Sr.b? command to read their values.
For example, to read the value of S-register S35, bit 7, type ATS35.7?
and press Enter. The modem responds with an appropriate value,
followed by OK.

Changing S Register Values

You can use the ATS0=n command to change the value of an S-
register.
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 U-336S/SA has an amount of memory set aside for storing user
information such as frequently used phone numbers and default
command settings. The latter is particularly useful when using your
modem to call a variety of different locations that require different
settings. For this reason, your modem provides a number of user
"Profiles" that can be accessed through simple AT commands. This
section covers the topics of storing phone numbers, and saving default
settings in the power-on profile.
20 Basic Modem Operation