Product specifications

Advanced Configuration

Silex

Page 33

Part Number 140-00188-180

Using AT Modem Commands

The Serial Device Server firmware has an optional data filter for configuring using AT style modem

commands with the serial port. This feature allows devices with an existing AT command interface to

configure the unit, if the AT commands can be properly modified. You must be familiar with the general

operation of AT commands. Note that AT command processing is not enabled by default. Use the

command SET PORT S1 FILTER AT to enable this feature.

All commands begin with AT and are terminated by a new line unless noted below. While standard AT

commands are defined to be 40 characters or less (not including the AT), the server accepts commands

of up to 80 characters.

Standard AT Commands Supported

The Serial Device Server recognizes a subset of the standard AT command set. The data channel must

be in the command mode for commands to be recognized. The data channel will be in command mode

upon power up or reset.

There are two operating modes for the unit when the AT command option is enabled. In command mode,

data received from the serial port is passed to the AT command processor, and responses are returned to

the serial port. No data is sent to any network application, and any data received from the network is

ignored. In data mode, data from the serial port passes to the network application, and vice versa. This

is equivalent to the normal serial port operating mode without the AT command option.

Table 8 describes the AT Commands. Table 9 details the Extended AT Commands that allow the

configuration of the network server operating parameters. Any AT command received, except the listed

commands, are acknowledged with OK status. This allows existing modem applications to transmit

commands without causing an error. These include AT<X>n, but not currently AT&<X>n, AT%<X>n,

AT\<X>n, where <X> is a letter.

Table 8 AT Commands

Parameter

Command

Description

Enter Command mode

If the string +++ is seen in data mode, with no

characters sent for 1 second before or after, then

command mode is entered.