Synxcom SM9234D, User Manual

Page: 67 / 216

AT Commands
Page 67
&R - 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.
Syntax &R<value>
Defined Values
<value> Decimal number corresponding to the option.
0 0 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.
1 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 <value> = 0 or 1.
ERROR Otherwise.
&S - DSR Override
This command selects how the modem will control DSR. The parameter value, if
valid, is written to S21, bit 6.
Syntax
&S<value>
Defined Values
<value> Decimal number corresponding to the option.
&0 DSR will remain ON at all times. (Default.)
&1 DSR will become active after answer tone has been
detected and inactive after the carrier has been lost.
Result Codes
OK <value> = 0 or 1.
ERROR Otherwise.
&X - Select Synchronous Clock Source
Selects the source of the transmit clock for the synchronous mode of operation.
The parameter value, if valid, is written to S27, bits 4 and 5.
In asynchronous mode, the transmit and receive clocks are turned OFF. In
synchronous mode, the clocks are turned ON with the frequency of 1200 Hz or
faster corresponding to the speed that is selected for modem operation.
Syntax
&X<value>
Defined Values
<value> Decimal number corresponding to the option.
0 Selects internal timing. The modem generates the
transmit clock signal and applies it to the TXCLK
output at the serial interface.
1 Selects external timing. The local DTE sources the