Rockwell RCV144ACx, Command Reference Manual

Page: 36 / 186

AT Command Reference Manual
3-18 1048
&Rn - RTS/CTS Option
This selects how the modem controls CTS. CTS operation is modified if hardware flow control is selected (see &K
command). The parameter value, if valid, is written to S21 bit 2.
&R0 In sync mode, CTS tracks the state of RTS; the RTS-to-CTS delay is defined by S26. In async
mode, CTS is normally ON and will turn OFF only if required by flow control.
&R1 In sync mode, CTS is always ON (RTS transitions are ignored). tracks the state of RTS; In async
mode, CTS is normally ON and will turn OFF only if required by flow control.
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.
&Sn - DSR Override
This command selects how the modem will control DSR. The parameter value, if valid, is written to S21 bit 6.
&S0 DSR will remain ON at all times. (Default.)
&S1 DSR will become active after answer tone has been detected and inactive after the carrier has
been lost.
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.
&Tn - Test and Diagnostics
The modem will perform selected test and diagnostic functions according to the parameter supplied. A test can be run only
when in an asynchronous operation in non-error-correction mode (normal or direct mode). To terminate a test in progress,
the escape sequence must be entered first, except for parameters 7 and 8 (see Section 3.1.3). If S18 is non-zero, a test will
terminate automatically after the time specified by S18 and display the OK message. Note: For tests 3, 6, and 7, a
connection between the two modems must first be established.
&T0 Terminates test in progress. Clears S16.
&T1 Initiates local analog loopback, V.54 Loop 3. Sets S16 bit 0. If a connection exists when this
command is issued, the modem hangs up. The CONNECT XXXX message is displayed upon the
start of the test.
&T2 Returns ERROR.
&T3 Initiates local digital loopback, V.54 Loop 2. Sets S16 bit 2. If no connection exists, ERROR is
returned. Sets S16 bit 4 when the test is in progress.
&T4 Enables digital loopback acknowledgment for remote request, i.e., an RDL request from a remote
modem is allowed. Sets S23 bit 0.
&T5 Disables digital loopback acknowledgment for remote request, i.e., an RDL request from a remote
modem is denied. Clears S23 bit 0. (Default.)
&T6 Requests a remote digital loopback (RDL), V.54 Loop 2, without self test. If no connection exists,
ERROR is returned. Sets S16 bit 4 when the test is in progress. The CONNECT XXXX message
is displayed upon the start of the test.
&T7 Requests a remote digital loopback (RDL),V.54 Loop 2, with self test. (In self test, a test pattern is
looped back and checked by the modem.) If no connection exists, ERROR is returned. When the
test is terminated either via expiration of S18, or via the &T0 or H command, the number of
detected errors is reported to the DTE. Sets S16 bit 5 when the test is in progress.
&T8 Initiates local analog loopback, V.54 Loop 3, with self test. (In self test, a test pattern is looped
back and checked by the modem.) If a connection exists, the modem hangs up before the test is
initiated. When the test is terminated either via expiration of S18, or via the &T0 or H command,
the number of detected errors is reported to the DTE. Sets S16 bit 6 when the test is in progress.
This command may not be available in some countries due to PTT restrictions.