User manual

About the Product
Campus-RS Fractional Interface Card User Manual 1-3
Furthermore, if a Campus-RS unit is connected over an HDSL link to an
earlier Campus product, and if either unit has the HDSL Transceiver (XCVR)
Mode set to AUTO, the HDSL link may not operate properly.
When operating the Campus-RS product with an earlier version of the
Campus products, to avoid any problems with link startup or operation, it is
recommended that the Transceiver Mode be set as follows:
• Campus-RS = MASTER
• Campus E1/T1/768 = SLAVE
If one or both units are already set to AUTO and the HDSL link is active,
disconnect the HDSL link, change the settings as recommended, and
reconnect the link. This will assure the link integrity on any subsequent
startups.
Channel Reversal
The current release of Campus-RS does not recognize HDSL loop reversal.
That is, the cable pairs must be “straight through,” with Loop A connected to
pins 1 and 2 of the Line Connector on both ends of the loop, and Loop B
connected to pins 4 and 5.
A possible symptom of loop reversal is to observe the LCD Margin on an RS
unit display during startup. The loop display will alternate between “ACK”
and “SIG” as expected. Then, one loop may display margin values as if the
link is synchronizing, but after 1 to 2 seconds will drop back to startup.
A future firmware release will allow automatic detection and compensation
for loop reversal.
This situation does not apply to a circuit with two Campus-RS
units. You may leave the units set to their default setting of
AUTO, and they will operate properly.