Chapter 7. Test Menu
7-8 TDU 120e User Manual 61202156L2-1
Run Self-Test
The self-test checks the integrity of the internal operation
of the electronic components by performing memory tests
and by sending and verifying data test patterns through
all internal interfaces. Although actual user data cannot
be passed during these tests, the self- test can be run with
the network and DTE interfaces in place and will not dis-
turb any external interface.
The memory portion of the self-test automatically exe-
cutes upon power-up.
A full self-test can be commanded from terminal/telnet
menu or from T-Watch PRO.
In addition to the specified self-tests, background tests are
also run on various parts of the internal electronics. These
run during normal operation to confirm continued cor-
rect functioning.
This menu selection is used to execute a full internal self-
test. The results of the self-tests are displayed on the ter-
minal. Upon invoking the command, the terminal dis-
plays System Self-Test and the Test LEDs are illuminated.
Test failures are displayed on the terminal.
The self-test consists of the following:
Test Name What it does...
Board level tests Each of the TDU 120e boards contains an on-
board processor which executes the following
series of tests checking the circuitry on the
board:
• RAM tests; EPROM checksum
• DS0 map tests
• On-board data path (sending a known test
pattern through an on-board loop)
Unit level tests Unit level tests consist of:
• Front panel LED verification
• Phase Lock Loop verification
• Board-to-board interface test
