AT Commands

Serial Port Ring Indicator (Pin 22) \R

The \R commands determine how the ring indicate signal operates on pin 22 of the EIA-232 DTE connector.

Command

Operation

 

 

\R

Causes ring indicate signal on pin 22 to turn on

 

(high) during each ring and remain on during the

 

call

 

 

\R1

Causes ring indicate signal on pin 22 to turn on

 

(high) during each ring and turn off (low) when the

 

call is answered

 

 

Request to Send / Clear to Send &R

When the modem is operating in nonbuffered mode (direct mode) or in synchronous mode, &R enables the RTS-to-CTS delay determined by the value in S26. &R1 forces CTS high and the modem ignores RTS (default). With &R2 selected, CTS goes high when carrier is detected. &R9 forces CTS to follow the state of RTS without delay.

Command

Operation

 

 

&R

Enables RTS-to-CTS delay

 

 

&R1

CTS forced on

 

 

&R2

CTS follows DCD

 

 

&R9

CTS equals RTS

 

 

Note

RTS/CTS delay is not valid in buffered mode or with error control enabled.

Note

With &R2 selected, XON/XOFF is the only valid method of flow control and &C and &C1 are the only valid carrier detect options.

Modem 3600

5-21

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Black Box 3600 MODEM manual Serial Port Ring Indicator Pin 22 \R, Request to Send / Clear to Send &R