Controlling Eia-232 Signaling; Data Terminal Ready - 3Com Courier Reference

8
Data Terminal
Ready
C
ONTROLLING
SIGNALING
This chapter contains information about configuring the EIA-232
signalling between your computer and modem:
Data Terminal Read
Data Set Ready
Carrier Detect
Your computer sends a Data Terminal Ready (DTR) signal to the Courier
V.Everything modem when it is ready to send and receive data. The &Dn
command tells the modem how to respond to the DTR signal.
For your modem to
Ignore the state of DTR and act as if DTR is always present. Use
this command with equipment that cannot provide DTR.
Enter online Command Mode during a call by dropping DTR, If
issued before connecting with another device.
Most communications software packages have a method for
toggling DTR. Refer to your software's manual for details.
Respond normally to the DTR signal.
The Courier V.Everything modem will not accept commands
until your computer sends a DTR signal. The call will end when
the DTR signal is dropped.
To change the DTR recognition time, set S-Register 25. See
Appendix A, S-Registers for more information.
1.The EIA-232 Standard was formerly known as RS-232 (RS stands for
Recommended Standard).
EIA-232
1
Command
AT&D0
AT&D1
AT&D2