Nortel Circuit Card Installation Manual page 471

Table 158
Connect and disconnect protocol (Part 11 of 12)
Mode of
operation Interface application
Mode 13 Hotline call origination
Mode 14 Terminal access for call
origination and answering
(with forced DTR)
NT7D16 Data Access card
Comments
Call disconnection (terminal):
Terminal toggles DTR from ON to OFF (DTR must
be OFF for 100 ms or more). The DAC turns DSR,
DCD, and CTS OFF for 0.2 second and then ON.
Terminal sends a long break or three short
breaks. The DAC turns DSR, DCD, and CTS OFF
for 0.2 second and then ON.
Hotline originated by terminal:
DAC drives DSR, DCD, and CTS ON in the idle
state.
Terminal toggles DTR from OFF to ON to initiate
Hotline call.
DAC responds by trying to establish a Hotline call
to a specific DM (Autodial).
If Data Module is busy or not responding, the DAC
requires another transition of DTR from OFF to
ON to initiate another Hotline call. If the terminal
keeps DTR ON, the DAC does not try to establish
another Hotline call unless the terminal sends a
<CR> while DTR is ON.
Call disconnection:
Disconnection is identical to mode 12.
Terminal access for call origination and
answering:
The DAC operation is identical to mode 12 except
that DTR is considered to be always ON, even
when the terminal is driving DTR OFF.
Circuit Card
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Description and Installation