Envoy Configuration and Management Manual

WAN Subsystem Profiles and Modifiers for Envoy
Envoy Configuration and Management Manual—429861-001
3-16
Modifier Descriptions
This modifier applies to SIMPLEX and ASC lines only. It enables DSRSENSE
capability for the asynchronous protocol. The loss of the DSR modem signal is sensed
and reported as an error during a READ or WRITE operation.
DTROFF
Default: DTRON
Units: Not applicable
Range: Not applicable
Alternate modifier: DTRON
This modifier applies to BSC lines only. It sets the Data-Terminal-Ready (DTR) signal
off.
DTRON
Default: DTRON
Units: Not applicable
Range: Not applicable
Alternate modifier: DTROFF
This modifier applies to BSC lines only. It sets the Data-Terminal-Ready (DTR) signal
on.
DUAL212
Default: Not specified
Units: Not applicable
Range: Not applicable
Alternate modifier: None
This modifier applies to SIMPLEX and ASC lines using Bell 212 modems (or the
equivalent of a 212 modem) only. It indicates that the speed of the modem should be
automatically sensed through the secondary carrier (SCF). A high signal indicates a
baud rate of 1200; a low signal indicates a baud rate of 300. If DUAL212 is specified,
the line must also be defined as switched (see the SWITCH modifier for more
information).
In addition, the CONTROL 17 function must be used to enable the connection. When
CONTROL 17 is issued, the driver sets the baud rate to 300 and the data-terminal-ready
signal is raised. When data-set-ready is detected, request-to-send is raised and the driver
waits up to 30 seconds for a clear-to-send signal. If clear-to-send is not detected, a
modem error is returned to the application. If clear-to-send is detected, the driver checks
for a secondary carrier and waits up to 30 milliseconds. If secondary carrier is detected,
the driver changes the line speed to 1200 baud.