Ber Test Generator; Telco Testing - Black Box MT160A Manual

MicroCSU/DSU Cards and MicroRacks
6.3 V.52 BER Test Generator
The MicroCSU/DSU has a built-in test pattern generator and detector. It can be
invoked at both ends of a link simultaneously, or it can be used with the Local
Analog or Remote Digital Loopback. The following example requires two
operators: one to initiate and monitor the test at the local MicroCSU/DSU
modem, and one at the remote MicroCSU/DSU modem. To use the V.52 BER
test by itself, both operators should simultaneously follow these steps:
1) Locate the "511/511E" toggle switch on the front panel of the
MicroCSU/DSU and move it to "511." This activates the V.52 BER test mode
and transmits a "511" pseudorandom test pattern to the other unit. If any
errors are received, the receiving CSU/DSU's red "Error" LED will blink
sporadically.
For this test to function, the "511" switch on both MicroCSU/DSU
modems must be on.
2) If the test indicates no errors are present, move the V.52 toggle switch to the
"511/E" test. The 511/E test transmits the 511 pseudorandom test pattern and
periodically injects intentional errors. If the test is working properly, the
receiving CSU/DSU's red "Error" LED will blink regularly. A successful 511/E
test will confirm that the link is in place, and that the MicroCSU/DSU's built-
in 511 generator and detector are working properly.
3) This test can be done by one operator by first activating the local analog loop
or remote digital loop.

6.4 Telco Testing

The digital service provider's central office can perform CSU Loop and DSU Loop
diagnostic testing. These diagnostics allow the central office to evaluate circuit
operation without making visits to a customer's premises.
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