Request to Send (RTS)

Request to Send (RTS) - pin 4

Request to Send, used to condition the modem for data transmission, is ignored when the modem is in online command, idle, dialing, or handshaking state. Once handshaking is complete and the online state is reached, RTS is tracked (except during carrier recovery) only if &Q1-&Q3 plus &R0 are in effect. If RTS goes on, CTS is turned on after the time delay specified by S26 (in 1/100 seconds) plus a maximum of 10 ms. If RTS goes off, CTS is turned off within 10 ms.

If &Q4 (Hayes AutoSync) is supported and in effect, and the modem is in the online state, RTS forces the modem receiver to reset and go into hunt mode. Hunt mode is when the modem looks for a new frame in either bisync or HDLC mode. This is used in bisync (BSC) mode when the application detects the end-of-frame.

RTS is ignored by the modem if one of the asynchronous DTE interface modes is selected (e.g., &Q0, &Q5, or &Q6).

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