Placing A Nondialed Call With An X.21 Dce; Figure 3-5: X.21 Nondialed Outgoing Call - PictureTel Concorde 4500 Servicing Manual

Placing a Nondialed Call with an X.21 DCE

This section describes the sequence of events that occurs when
the Concorde¥4500 initiates a nondialed call and later disconnects
the call.
1. The Concorde•4500 starts the call by transmitting data and asserting its
C signal.
2. When the far end answers and begins sending data, the DCE responds
by asserting its I signal and placing the far-end data on the R signal to
the Concorde•4500.
3. The Concorde•4500 disconnects the call by setting the T signal to
binary 1 and deasserting its C signal.
4. When the far end responds to the loss of data by disconnecting, the
DCE returns to the Ready state by placing binary 1 on its R signal and
deasserting its I signal.

Figure 3-5: X.21 Nondialed Outgoing Call

Call
requested
Ready
X.21 Call Setup and Disconnect
Ready
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