19
MODULAR FIBER CAMPUS DRIVER, MFCD PLUS
NOTE
Although the local Campus Driver cannot communicate with the remote
Campus Driver in this mode, the synchronized connection between the
two modems remains intact.
2. Verify that the data terminal equipment is operating properly and can be
used for a test. If a fault is indicated, call a technician or replace the unit.
3. Perform a BER (bit error rate) test on each unit using a separate BER tester.
If the BER test equipment indicates no faults but the data terminal indicates a
fault, follow the manufacturer’s checkout procedures for the data terminal.
Also, check the interface cable between the terminal and the Campus Driver.
5.3.2 R
EMOTE
D
IGITAL
L
OOPBACK
The Remote Digital Loopback test checks the performance of both the local and
remote Campus Driver, and the communication link between them. Any
characters sent to the remote unit in this test mode will be returned back to the
originating device (see
Figure 5-2
).
Figure 5-2. Remote digital loop.
To perform an DL test, follow these steps:
1. Activate DL. This may be done in one of two ways: First, by moving the front
panel toggle switch DOWN to “Remote.” Or, second, by raising the DL signal
on the terminal interface (for pin numbers, see the
Appendix
).
2. Perform a BER (bit error rate) test on the system, using BER testers on both
ends.
