Avaya Definity SI Maintenance Manual page 867

ANL-16-L (16-Port Neon Analog Line)
Loop Around Test (#161)
Each Analog port consists of:
an NPE for port connectivity and gain, and conferencing functionality
a code that converts the digital signals of the TDM Bus to analog signals
a battery feed chip that provides power to the telephone set for signaling,
dial pulsing, transmission, and balance
This test is designed to check the on-board transmission capabilities of the NPE,
the codec, and the battery feed chip of the analog port. A Tone Detector and a
Tone Generator talk and listen on the same pair of time slots as the Analog Port.
The Analog Port is then instructed to go into loop around mode (see the following
below). The test passes if the signal measured by the Tone Detector is within
acceptable limits.
* BFC - BATTERY FEED CHIP
NPE - NETWORK PROCESSING ELEMENT
Figure 10-2. Analog Loop Around Test
555-233-123
TONE
LEVEL
MEASUREMENT
CODEC
TONE
SOURCE
TDM BUS
Issue 4 May 2002
BFC*
TN746B
TN468,
etc.,
PORT
NPE*
10-81