Black Box MD885C-R2 Modem User Manual


 
52
Modem 34336
Enable — The Modem will check for X-ON/X-OFF (DC1/DC3)
flow control characters received from the remote modem to determine
whether to stop or start/restart data transmission to the remote modem.
A DC3 (or DC2) control character will cause the Modem/Modem 3242–S
to stop data transmission and hold data in its buffer until it receives a DC1
control character (which instructs the modem to resume transmission).
Disable — The Modem will ignore X-ON/X-OFF (DC1/DC3)
flow control characters received from the remote modem.
Slaved — Link flow control is controlled by the DCE-DTE Flow Control
option. If DCE-DTE Flow Control is set to NONE or CTS, Link Flow
Control is disabled. Otherwise, it is enabled.
The V.32 Mode option Hayes, V.25 bis, Dumb, and Leased-Line modes
(except V.33)
This option is used to select CCITT V.32 bis operation or V.32 extended
operation.
When V.32 bis mode is selected (factory-default setting), the follow-ing are
available: RRP (Rate Renegotiation Procedure); data rate of 7200 bps; RATE
screen that allows you to manually initiate RRP. RRP enables the modem to
auto-matically fall back or fall forward to a lower or higher data rate during
data transmission in response to changes in signal quality. Selecting V.32 bis
mode makes RRP available as an option; however, RRP will not function unless
it is enabled (the default setting is enabled.)
When V.32 bis mode is selected, a RATE screen is available from MAIN
MENU screen 3. The RATE screen can be used to manually initiate RRP
for diagnostic purposes. For additional informa-tion, see Section 7.6,
Diagnostic Monitoring: Status Screens.
When V.32 bis mode is selected, 7200 bps can be selected as the maximum
or minimum data rate (using the Speed Limit option). When V.32 bis is not
selected, 7200 bps operation is not available.
NOTE
By definition, V.32 bis operation includes the ability to operate at 12,000 and 14,400
bps. Therefore, only the Modem is a true V.32 bis modem. However, when the
V.32 bis mode is selected on the Modem 32192, it will support the following
options as well: RRP; 7200 bps data rate; the RATE screen.
The V.32 extended mode disables the V.32 bis features. In V.32 extended
mode, the Modem’s functional ability is identical to that of previous models
of this modem series (the MD833A model prior to incorporation of the
CCITT V.32 bis recommendation.)