Asynchronous Terminals and Printer Processes Programming Manual

TERMINAL I/O
Timeouts
Transmit pause, reverse channel, and automatic baud rate detec-
tion all use pin 12 (SCF) of the RS-232 connector. Therefore,
only one of them can be selected at a time.
Timeouts
Operations with terminals require human response and therefore
can take an indefinite period of time. Use the time-limit
parameter of the AWAITIO procedure to ensure that a terminal
operator performs an operation within a given period of time.
The terminal must have been opened to permit nowait I/O. For
example, an application program prompts a terminal operator for
an account number. If no entry is made within the time specified
in the time-limit parameter, an error 40 is returned and the
application program reminds the terminal operator by reprompting.
The SYSGEN TIMEOUT modifier applies only to 6530 terminals using
the ENQ/ACK protocol.
November 1987 2-17