On-Line Abort Conditions - Tandy DCM-7 Operation Manual

Tandy protocol mode operation
Always auto-answer mode operation
The Modem assumes always automatic answer mode operation when the DIP
Switch 6 is set to on at power up, and begins monitoring the telephone line.
When you type
* ,
the Modem enters command receptive mode and changes
to automatic originate mode as i:ri normal automatic answer mode. After dis-
connecting, or after receiving the C (clear memory) command, the Modem
returns to automatic answer mode.
This setting is useful when you use the Modem mainly in the answer mode.
On-line abort conditions
After establishing communications with a remote modem, the DCM-7 is in
monitor mode. In this mode, the parameters are constantly scanned. If any
one of these parameters fails, the DCM-7 will break communications and
go OFF LINE immediately. The parameters monitored include loss of carri-
er, the abort character and space disconnect.
Loss of carrier
The carrier monitored is the one that is sent over the telephone line, not the
false carrier generated by the DCM-7. In all modes, except TEST, if carrier
is removed for longer than 0.3 seconds, the Modem will exit monitor mode
and drop the phone line. If the carrier interruption is less than 0.3 seconds,
loss of carrier is ignored.
In automatic originate mode, when the Modem is waiting for a call to be
completed (a 30'-second delay time between dialing and disconnect where the
DCM-7 is looking for a valid carrier signal), you can command the DCM-7
to abort the call by inputting any keys including
*.
If you aborted with other
keys, press
~to
set the Modem to command receptive mode.
Manual abort entry
When you send a CTRL
0 (OF
HEX) or another character you programmed
with the
@
key and do not send any other character for 2 seconds, the DCM-7
will exit monitor mode.
DTR (Data Terminal Ready) is also scanned in this mode. If the DTR is OFF,
the DCM-7 will terminate communications, just as if the carrier had failed.
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