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AT&D2).
The convertor modems in a pool for outgoing calls should be configured as follows:
-
Switched line configuration;
-
non-silent mode (result codes enabled, Hayes command ATQ0);
-
CT107 indicates the state of the analogue connection (according to the V.24 specification,
Hayes command AT&S1);
-
when CT108 changes from ON to OFF the modem must go on hook (Hayes command
AT&D2).
C.4.1. Incoming Call
Figure
Figure C-4 Call Phase Diagram for an Incoming Call.
an incoming call. In order to understand the call phase diagram note the following:
-
a circuit number means that the circuit is in the ON state (active);
-
a circuit number followed by a `O' means that the circuit is in the OFF state (deactive);
-
the conversation mode during data transfer and clearing is not described (CT105 and
CT109 interactions).
DTE-B dials the convertor group DNR (ALC side of convertor pool) using for example Hayes
commands.
MODEM-A detects an incoming call (ring current) and activates CT125. In return the
SOPHO-LAM activates CT107 which is connected to CT108 of MODEM-A. Because
MODEM-A operates in the automatic answering mode, it answers the call after receiving an
active CT108. The SOPHO-LAM keeps CT107 active as long as the call exists.
shows the call phase diagram for
103
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