7-3
Compaq Integrated Remote Console User Guide
Writer: Caroline Juszczak Project: Compaq Integrated Remote Console User Guide Comments: 281862-002
File Name: H-CH07.DOC Last Saved On: 12/21/98 11:08 AM
COMPAQ CONFIDENTIAL - NEED TO KNOW REQUIRED
■
DTR Control — For compatibility with IRC, the terminal must assert
DTR whenever a communication session is open. IRC uses the DCD
control signal (which is driven by the terminal’s DTR output) to
determine whether a remote session is open. IRC ignores any serial port
activity whenever DCD is inactive. Consequently, if the terminal does
not assert it’s DTR output, it is impossible to establish a connection with
IRC. Conversely, the terminal must lower DTR whenever a
communication is closed. This ensures that the current user is properly
logged out and IRC will return to a passive state.
■
DCD Interpretation — IRC asserts it’s DTR serial port control signal
whenever it is prepared to accept an incoming login request. Through
the null-modem cable, this signal is wired to the terminal’s DCD input,
which is usually reflected by the terminal’s status bar as “CARRIER” or
“ONLINE.” IRC drops DTR in response to a logout or close session
request.
