User's Guide

8400B Plus Data Module User’s Guide 555-020-709
Issue 2
November 1996
AT Command Set
A-23
Command: &D
Function: Data Terminal Ready (DTR) options.
Type: configuration
Arguments: The &D command accepts one of four arguments as
follows:
0 — ignore the DTR interchange circuit (factory-default
setting).
1 — return to the command state if an on-to-off
transition is detected on the DTR input; an active data
call is
not disconnected.
2 — go on hook when an on-to-off transition is detected
on the DTR input (EIA/TIA-574 standard); an active
data call
is disconnected.
3 — perform a reset if an on-to-off transition is detected
on the DTR input; an active data call is disconnected.
S-Register: Bits 3 and 4 of S21 are set according to the option used
with the &D command.
Example: AT&D2
Comments: In the example, the DTR circuit is set according to the
EIA/TIA-574 standard. This would be an appropriate
setting for when the 8400B Plus Data Module is used at
a remote site as a dedicated device to automatically
answer an incoming data call.
If the change of state for the DTR circuit persists for a
time shorter than specified in S25, the change is
ignored.
See Also: S-register S21 on page C-25
.
Table A-1. Accepted AT Command Labels
Label Description
ENTER
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