Specifications

Chapter 4. Troubleshooting & Diagnostics FOMi-E1/T1 Installation & Operation Manual
4-10 Diagnostic Tests
8. To stop the test, press the SCROLL button until OFF is displayed and
then press the ENTER button.
The message WAIT... is displayed on the local modem LCD and the test
is terminated.
Internal BER Tester
and Pattern
Generator
Operation
FOMi-E1/T1 has a built-in BER Tester and Pattern Generator which, together
with the V.54 diagnostic loops and a remote BER tester, can check normal
system operation and isolate faulty equipment in the event of system failure.
The Pattern Generator, which is automatically activated when the BER
Tester is activated, sends a 511 pattern according to the ITU V.52 standard.
If errors are detected by the BER tester, the ERR LED indicator blinks or
remains on. Figure 4-9 describes the data flow for the operation of the
internal BER tester and the Pattern Generator.
The BERT test can be activated simultaneously on both the local modem
and the remote modem, thus checking the integrity of the link from both
sides of the application at the same time.
LOCAL FOMi-E1/T1 REMOTE FOMi-E1/T1
FIBER
FIBER
FIBER
FIBER
ERR
PATTERN
TESTER
PAT T ERN
TESTER
PATTERN
GENERATOR
RCVR
XMTR
REMOTE
DATA
TERMINAL
(511 PATTERN
MODE)
Figure 4-8 FOMi-E1/T1 Internal BER Test
Note
In FOMi-E1/T1 mode of operation, the internal BERT can be performed with
an external BER tester. In such a case, the zero suppressing function of the
tester must be disabled (AMI code).
The BERT test is initiated by the user at the local modem. For this test, the
modem's internal 511 pattern generator generates a message. The message
is sent to the remote modem, and from the remote modem is returned by
the remote DTE. When this test is performed, the remote DTE has to be in a
511 mode of operation. The local DTE is disconnected when this test is
running.
The BERT is the only test that can be executed from both sides of the line
simultaneously. Both modems can initialize their own tests and each LCD
will display the BER in the Menu Options field.
➤
➤ ➤
➤
To activate a BER test:
1. Press the CURSOR button to move to the Menu Type field.
2. Press the SCROLL button until Tests is displayed.