insys icom i-modul 144/56k, Designer'S Manual, Page: 38 / 63

AT Command Reference i-modul Modem 144/56k
Command Description
ATP
Switch on pulse dialling method (deactivated for some models)
Starting with this command, each dial-up is performed with the pulse dialling
method, until an
ATT
or
ATDT
command switches it back to tone dialling.
ATQ<n>
Quiet control
This command enables or disables sending messages from the i-modul Modem
144/56k 3.0 basic to the application.
ATQ0
Send messages to the application (default)
ATQ1
Don’t send messages to the application
AT%Q
Displaying the quality of the telephone connection
Displays the quality of the data connection (deviation from the eye diagram). Low
values indicate a good line quality. The line quality value must be evaluated differently
depending on the negotiated data rate.
Connections with more than 9600 baud will reach the value "000" for good lines and
should not have values of more than "010".
For connections with 33600 baud good lines will have values between 010…030.
Depending on the settings and the modulation type a fall back or retrain is triggered if
the line quality is too bad to enable a new negotiation of the connection (if necessary
with a slower speed).
High values indicate bad quality. These values are constantly updated during a
connection. If the value increases significantly during a connection, the quality
will deteriorate. After a previous
AT%E
command, an
Autoretrain is performed.
AT&R
RTS/CTS behaviour
This command determines how the modem treats the RTS/CTS (CT105/CT106)
data flow control lines (refer also to the command
AT&K<n>
).
AT&R0
CTS behaviour complies with V.25bis. CTS is deactivated during
the connection setup after recognition of the response or ringing
tones and will only be activated after the connection is set up.
AT&R1
CTS only switches to OFF when this is required by the data flow
control (default).
ATS<n>
Reading/writing the S registry
Depending on the country settings, the S registers may only be changed within
certain limits. The i-modul Modem 144/56k 3.0 basic still reports
OK
, although the
value has not changed as specified. We recommend checking the results after
each write attempt, using the
ATS<n>?
command.
ATS<n>=<x>
Sets the S register n to the value
x
ATS<n>?
Shows the value of the S register
n
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