Chapter 5 – AT Commands, S-Registers, and Result Codes

Command: &R

RTS/CTS Option

Description:

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.

Default:

None

 

 

Defined Values:

&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

 

 

 

Otherwise ERROR

Command: &S

DSR Override

Description:

Selects how the modem will control DSR. The parameter value, if valid, is

 

written to S21 bit 6.

Default:

0

 

 

Defined Values:

&S0

DSR will remain ON at all times.

 

&S1

DSR will become active after answer tone has been detected and

 

 

inactive after the carrier has been lost.

Result Codes:

OK

 

 

 

Otherwise ERROR

Command: +IPR

Fixed DTE Rate

Description:

This numeric extended-format parameter specifies the data rate at which

 

the modem will accept commands during online operation. It may be used

 

to select operation at rates at which the modem is not capable of

 

automatically detecting the data rate being used by the DTE. Specifying a

 

value of 0 disables the function and allows operation only at rates

 

automatically detectable by the modem. The specified rate takes effect

 

following the issuance of any result code(s) associated with the current

 

command line.

 

The <rate> specified does not apply in Online Data State if Normal Mode

 

(Direct Mode) of operation is selected.

Default:

None

 

 

Defined Values:

<rate> Specifies the DTE-modem interface operation rate in bits/s.

 

The available rates are 0, 300, 1200, 2400, 4800, 9600, 19200, 38400,

 

57600, 115200, or 230400.

 

If unspecified or set to 0, automatic detection is selected and the character

 

format is also forced to autodetect, +ICF=0.

 

If the rate specified is not supported by the modem, an ERROR result code

 

will be returned.

Report Commands:

+IPR?

Reports current rates

 

+IPR=?

Reports current range Example: +IPR:

 

(0,300,1200,2400,4800,9600,19200,38400,57600,115200, 230400)

Multi-Tech Systems, Inc. SocketModem MT5600SMI Developer’s Guide

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Multi-Tech Systems MT5600SMI-XL34 Command &R RTS/CTS Option, Command &S DSR Override, Command +IPR Fixed DTE Rate, +Ipr?