Black Box 3600 MODEM manual Data Set Ready &S, Data Terminal Ready &D

AT Commands

Data Set Ready &S

These commands control the DSR signal generated by the modem to indicate that the modem is ready for operation. DSR must be on for some terminals and devices to communicate with the modem.

Command	Operation
&S	DSR always on
&S1	DSR on when off hook in data mode
&S2	DSR off for 5 seconds after disconnect then returns
	to on
&S3	DSR follows off hook (OH) signal

Data Terminal Ready &D

In data mode DTR may be used for modem control.

Command	Operation
&D	The modem ignores DTR.
&D1	The modem goes to command mode from data
	mode when DTR goes from on to off.
&D2	Disconnects when DTR goes from on to off;
	disables autoanswer while DTR is off.
&D3	Disconnects, recalls command mode, and resets the
	modem to a stored configuration when DTR goes
	from on to off.
	In dial line mode the modem disconnects; in leased
	line, the modem retrains.

Note

If DTR controls dialer is selected, selecting DTR active will cause an autodial after an off-to-on transition of DTR.

5-20 Modem 3600