Hardware manual

5901 High Speed Dialup Modem Hardware Manual
October 19, 2007
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10.1.2 Escape Code Sequence
When the 5901 modem has established a connection and has entered on-line data mode, it is
possible to break into the data transmission in order to issue further commands to the modem in an
on-line command mode. This is achieved by the DTE sending to the modem a sequence of three
ASCII characters specified by register S2. The default character is '+'. The maximum time allowed
between receipt of the last character of the three escape character sequence from the DTE and
sending of the OK result code to the DTE is controlled by the S12 register.
10.2 AT Command Set
The 5901 modem will respond to the commands described below. Parameters applicable to each
command are listed with the command description.
The default values, as shown for each configuration command, are those used in the 5901 modem
factory profile 0.
10.2.1 A/ - Repeating a Command Line
If the prefix "A/" or "a/" is received, the modem immediately executes once again the body of the
preceding command line. No editing is possible, and no termination character is necessary. A
command line may be repeated multiple times in this manner. Responses to the repeated command
line are issued using format of the original command line. If "A/" is received before any command
line has been executed, the preceding command line is assumed to have been empty (that results in
an OK result code).
10.2.2 AT - Read/Write S Parameter
The modem selects an S-Parameter, performs an S-Parameter read or write function, or reports the
value of an S-Parameter.
n Establishes S-Parameter n as the last register accessed.
n=v Sets S-Parameter n to the value v.
n? Reports the value of S-Parameter n.
The parameter n can be omitted, in which case the last S-Parameter accessed will be assumed. The S
can be omitted for AT= and AT?, in which case the last S-Parameter accessed will be assumed.
For example:
ATS7 establishes S7 as the last accessed register.
AT=40 sets the contents of the last register accessed to 40.
ATS=20 sets the contents of the last register accessed to 20.
If the number "n" is outside the range of the S-Parameters available, the modem will return the
ERROR message. If the value “v” is outside the range permitted for a given S-Parameter, the modem
will return the ERROR message. Input and output are always in decimal format. Note that some S-
Parameters are read-only.
In some cases, writing to the S-Parameter will appear to be accepted but the value will not actually
be written.
Due to country restrictions, some commands will be accepted, but the value may be limited and
replaced by a maximum or minimum value.