Actiontec electronic IS560LH user manual Data Carrier Detect DCD Control, DTR Control

Result Codes:

	OK	n = 1
	ERROR	Otherwise
&Cn		Data Carrier Detect (DCD) Control

Data Carrier Detect is a signal from the modem to your computer indicating that the carrier signal is being received from a remote modem. DCD normally turns off when the modem no longer detects the carrier signal.

	Command		Effect
	&C0		The state of the carrier from the remote modem is
			ignored. DCD circuit is always on.
			DCD turns on when the remote modem’s carrier signal
	&C1		is detected, and off when the carrier signal is not
			detected (default).
Result Codes:
	OK	n = 0, 1
	ERROR	Otherwise
&Dn		DTR Control

This command interprets how the modem responds to the state of the DTR signal and changes to the DTR signal.

Command	Effect
	Ignore. The modem ignores the true status of DTR and
&D0	treats it as always on. This should only be used if your
	computer does not provide DTR to the modem.
	If the DTR signal is not detected while in on-line data
&D1	mode, the modem enters command mode, issues OK
	result code, and remains connected.
	If the DTR signal is not detected while in on-line data
&D2	mode, the modem disconnects (default). If this signal is
	not present, the modem will not answer or dial.
	Monitor DTR signal when an on-to-off transition occurs,
&D3	the modem performs a soft reset as if the ATZ
	command was received.

Result Codes:

OK	n = 0, 1, 2,
	3
ERROR	Otherwise

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