Lucent Technologies 7400B Telephone User Manual


 
APPENDIX A: AT COMMAND SET
DEFINITY Communications System
7400B Data Module
Page A-12
User’s Guide
Command:
&C
Function:
Data Carrier Detect (DCD) options.
Type:
configuration
Arguments:
The &C command accepts one of two arguments as follows:
0 - (or no argument) maintain the DCD circuit on at all times
(factory-default setting)
1 - the DCD circuit operates according to the EIA-232-D standard
S-Register:
Example:
Comments:
Bit 5 of S21 is set according to the argument used with the &C
command.
at&c1
[ Enter ]
In the example, the DCD circuit operates according to the EIA-232-D
standard. This would be an appropriate setting for when the 7400B
Data Module is used at a remote site.
Regardless of which option is currently in effect, the DCD circuit of
the 7400B Data Module is always off during self-test, and turns off for
0.5 second during a disconnect sequence.
See Also:
Chapter 4, “Operation and Configuration”; Appendix B, “S-
Registers.”