Note
2
: You can use the Model 2500 Series to transmit lower-speed
asynchronous data (up to 9.6 kbps) over synchronous circuits by simple
over-sampling. To do this, select the synchronous data format and set
the line Line Rate (Software Switch Menu option 1) to at least four times
that asynchronous data rate you wish to send. For example, use a Line
Rate of 9.6 kbps or higher for 2.4 kbps async data.
DSR Status During Local Loopback
Choosing option 6 in the Software Switch Menu takes you to the
DSR Loop Status Menu (below). This option controls the behavior of
the DSR output during local loopback. To force DSR high (ON) during
local loopback, enable this option. To force DSR low (OFF) during a
local loopback, disable it.
Rate Converter/DTE Rate
Choosing option 7 in the Software Switch Menu takes you to the
Rate Adapter/DTE Rate Menu (opposite page). The Model 2500 Series
rate converter adapts a 56 kbps or 64 kbps line rate to slower DTE data
rates. Set the Rate Converter to match the DTE data rate. If the DTE
data rate is the same as the line rate, disable rate conversion by
selecting item 6 on this menu.
(continued)
19
20
Note: For DTE data rates of 56 kbps or 64 kbps, set the rate adapter to
“Line Rate = DTE Rate”, and the line rate to 56 or 64 kbps, respectively.
For DTE rate of 57.6 kbps, set the rate adapter to “Line Rate =
DTE Rate”, set line rate to 56 kbps, set DTE for two stop bits, and set
CSU/DSU character length to “11 bits”.
DTE Loop Control
Choosing option 8 in the Software Switch Menu takes you to the
DTE Loop Control Menu (below). The local and remote loopbacks on
the Model 2500 Series can be controlled from the DTE interface by
raising or lowering the LL and RL signals. To allow the DTE to control
these loopbacks in this manner, enable this option. Disable if you want
the Model 2500 Series to ignore these signals.
(continued)
