tcl.dcd Verb: Access/TCL

tcl.dcd

Command tcl.dcd Verb: Access/TCL
Applicable release versions: AP, R83
Category TCL (746)
Description toggles or displays the status of data carrier detect on the specified port.

If the port number is not specified (as an option), dcd is toggled on the current port.

When activated, this protocol allows the system to sense changes in the dcd signal. When the system senses a loss of the dcd signal on a port, it logs the port off.

Without any option, the status of the specified port is displayed.

On AP/Unix implementations, options and parameters are interchangeable.

This command affects the argument "clocal" of the terminal driver, when the "f" option is used.

When the dcd is lost, the process is interrupted by a Unix HANGUP signal which forces it to execute the TCL command specified by the "trap" command. (see "trap, TCL, Verb").

An appropriate cable must be used to connect the system to the modem for the dcd signal to be detected. When the "n" option is used, the terminal driver is changed to "-clocal".
Syntax dcd {(options}
Options n (integer number) Displays or changes settings for port n.

f Toggles dcd off. Data carrier detect is inactive.

n Toggles dcd on. Data carrier detect is active.

s Suppresses output of status message.

x Displays the current carrier detect status (x is any character other than "f", "n", or "s")
Example
dcd
[1311] Data carrier detect is off.
Tests the current state of dcd.

dcd ?
[1311] Data carrier detect is off.

dcd n
[1310] Data carrier detect is on.

dcd 16 fs

(No output appears. This turns off dcd on port 16 and suppresses the output).
Purpose
Related tcl.trap
tcl.dcd-off
tcl.dcd_rp
tcl.fc
tcl.fc-off
tcl.fc-on
tcl.modem-off
tcl.modem-off_rp
port.number
tcl.dcd-on
tcl.list-jobs
general.hangup