NT7D16 Data Access card Page 455 of 894
Circuit Card Description and Installation
Mode 8 Host access for call
origination and answering
Host answering an incoming data call:
Local DM user dials the access number to initiate
the connection.
DAC responds by driving RI ON for 2 seconds and
OFF for 4 seconds until the Host answers by
turning DTR ON. (If the Host always drives DTR
ON, the DAC immediately answers the call
without driving RI ON.)
When Host receives RI ON, it should respond by
turning DTR ON.
DAC answers when it receives DTR ON.
DAC turns DSR, DCD, and CTS ON when the call
is completely established. The local DM user is
now transparently linked to the Host.
Host originating a data call:
Host turns DTR ON to initiate the connection.
DAC prepares to receive <CR> for autobaud.
Host sends <CR> followed by other commands
for establishing a data call (the DAC does not
echo a command, nor does it send any prompt to
the Host (blind dialing).
When the data call is completely established, the
DAC turns DSR, DCD, and CTS ON as long as
the call is connected.
Table 153
Connect and disconnect protocol (Part 7 of 12)
Mode of
operation Interface application Comments