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Chapter 4 - Commands
4.3.1 AT Commands and S-Register Summary
The vast majority of installations are similar, with the MT2834 being used
to dial up a remote installation where the call is automatically answered.
Your MT2834 has a default configuration to dial another 33,600 bps
modem that support error correction, data compression and flow control. If
the answering modem is not compatible, the MT2834 can match protocols,
provided the protocols are industry standard (i.e., ITU-T or Bell) and not
proprietary.
The &W command, used in conjunction with specific other AT commands
and S-Registers, can reconfigure the MT2834 to conform to a specific
application. The MT2834 can store its configuration parameters and S-
Register values in its nonvolatile memory.
The command AT&W0 (or AT&W) causes the modem to store its current
parameters in its nonvolatile RAM. The command also sets the modem
upon power up, or when it is reset with an ATZ command, the modem
reads all its configuration and S-Register parameters from RAM, and not
from the factory settings in ROM (note you may recall factory installed
defaults by entering AT&F8&W0). The &W command changes the
configuration parameters stored in RAM that you specifically intend to alter.
All other default parameters remain unchanged.
The AT&W1 command sets the modem so that it does not store its
parameters in RAM, and on power up or when an ATZ command is issued,
parameters are read from the factory default settings in ROM.
Before using the &W command, you may want to view the modem's
current operating parameters. Use the ATL5, ATL6 and ATL7 commands
to display the current modem configuration.