Asynchronous Terminals and Printer Processes Programming Manual

TERMINAL I/O
Modem Characteristics
Table 2-8. Modem Control Characteristics
SYSGEN CONTROL CMI
Characteristic Modifier Parameter Attribute
_______________________________________________________________
Automatic baud rate DUAL212 (none) AUTOBAUD
detection
(300/1200 baud)
Automatic disconnect AUTODCONNECT 67 AUTODCONN
Half duplex HDTURN1 (none) HDXTURNCHAR
turnaround character HDTURN2
Wait for modem (none) 11 (none)
connect
Disconnect modem (none) 12 (none)
When automatic baud rate detection is enabled, the SDCD signal
determines the baud rate of the modem. This option is available
only for Bell 212-type modems. Allowable baud rates are 300 and
1200. If SDCD is high, the baud rate is 1200; if it is low, the
baud rate is 300.
The AUTODCONNECT SYSGEN modifier supports European CCITT-
standard, full-duplex modems. When automatic disconnect is
enabled, the I/O process monitors carrier detect (CD) as well
as data set ready (DSR). If an error occurs during processing
of a modem connect (CONTROL 11) procedure call, the system
ensures that the communication line is disconnected. For ATP6100
subdevices, you can change the SYSGEN default by including the
AUTODCONN attribute in a CMI ALTER SU command.
Certain modems and terminals require one or two special
turnaround characters for switching between send and receive
modes. The HDTURN1 and HDTURN2 SYSGEN modifiers specify these
characters. For ATP6100 subdevices, you can change the SYSGEN
default by including the HDXTURNCHAR attribute in a CMI ALTER SU
command.
After subdevices have been configured, use the CONTROL procedure
call to activate and deactivate the modem. CONTROL 11 directs
the application to wait for the modem connection. CONTROL 12
disconnects the modem without closing the file.
2-16 November 1987