Nortel Circuit Card Installation Manual page 465

Table 158
Connect and disconnect protocol (Part 5 of 12)
Mode of
operation Interface application
Mode 5 Inbound Hotline Gateway
access
NT7D16 Data Access card
Comments
Call disconnection (DAC):
DAC drops DTR if the local DM user drops the
call. The Gateway must drop DCD.
DAC drops DTR if the DAC receives a long break
or three short breaks. The Gateway must drop
DCD.
Call disconnection (Gateway):
Gateway drops DCD (DCD OFF for 100 ms or
more). The DAC drops DTR and disconnects the
local call.
Gateway drops DSR (DSR OFF for 100 ms or
more). The DAC drops DTR and disconnects the
local call.
Inbound Hotline Gateway protocol:
Gateway raises DCD to initiate connection.
DAC responds by trying to establish a Hotline call
to a specific Data Module (Autodial).
When Data Module answers, then and only then,
the DAC turns DTR ON.
Gateway does not have to turn DSR ON.
However, toggling DSR or DCD from ON to OFF
causes the DAC to drop the call.
Gateway is not transparently linked to the
equipment connection to the DM.
Call disconnection:
Disconnection is identical to mode 4.
Circuit Card
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Description and Installation