SECTION 5
TESTS
OVERVIEW
This section describes the tests that may be performed on the CELP Voice
Channel Module after installation. These tests are performed using a
TMS/Supervisory controller and are used to isolate problems in the data
communications system. Tests are performed through the CELP Voice
Channel Module base and piggyback card only. A Technical Assistance
procedure and CELP Voice Channel Module test point location is given at
the end of this section.
DATA PATH TESTS
Digital Test
This test is performed in conjunction with a digital local or remote loop-
back test. The test performs a rudimentary error rate check on the digital
portion of the channel module through the multiplexer network or in a lo-
cal loop. An alternating "ones and zeroes" pattern is transmitted from
the CELP Voice Channel Module and received from either the local or
remote CELP Voice Channel Module. Errors are counted at the receiving
end. This test causes a channel alarm to be raised and forces the E-lead
to a Busy state to prevent access by a PBX.
Control State Test
The Control State Test forces the M-Input at either end of the channel to a
"busy" state. The E-lead at the remote end should be "Busy" as a result of
the M-signal sent.
User Data Test
The User Data Test creates a test path for use with external test equip-
ment. When User Data Test is selected, the user voice data is looped ei-
ther locally or at the remote end. Local loopback is performed at the digi-
tal section of the local CELP Voice Channel Module card. Remote loop-
back is performed at the analog section of the remote CELP Voice Chan-
nel Module. Remote loopback includes almost all of the circuitry on both
CELP Voice Channel Modules.
1 kHz Tone Test
This test sends a 1-kHz tone through the test path.
The channel module at the origin node generates a 1-kHz tone. This tone
is then digitized and sent through the selected path.
In a circuit remote loopback test, the 1-kHz signal loops back at the ana-
log section of the module. In a channel local test, the signal loops back in
the digital section of the module.
The 1-kHz tone may be monitored by connecting external test equipment
to the VF Out front panel test point of the originating channel.
5-1
