Line 2 Mb/S, Pcm31Crc, Terminated & Re-Timing - Wavetek ANT-20 Operating Manual

ANT-20SE
3.3 Line 2 Mb/s, PCM31CRC, terminated & re-timing, full test (approx. 25 min)
Commissioning a structured 2 Mbit/s communications line
Use the "Line 2 Mb/s, PCM31CRC, terminated & re-timing, full test (approx. 25 min)" application
if you intend to commission a structured and terminated 2 Mbit/s PCM31CRC line.
Special features
If the desired or required properties of the line to be tested are known (transparent or structured
lines), a check is first made to see if these properties are present. The in-depth measurements
(e.g. MTJ, G.826, jitter) are performed after this.
Connecting the item under test
The balanced or coaxial output and input sockets of the item under test are connected to input
[12] or [14] of the receiver (RX) and output [13] or [15] of the generator (TX) for the "Line 2 Mb/
s, PCM31CRC, terminated & re-timing, full test (approx. 25 min)" application.
Measurement
The following typical line parameters are expected:
Typical line parameter
Frames
CRC
Re-timing
Termination for FAS and CRC
CRC-4 / E bit detection
Table SA-2
Note: The clock pulling range is not measured, since "re-timing" is used. All measurements
The following measurements are then performed:
Test
Alarm sensor test LOS → AIS_64k
Alarm sensor test LOS → RDI
Alarm sensor test RDI → RDI
Signal delay < 22 ms "round trip"
Intrinsic jitter HP1 (10 Hz/100 kHz):
< 1.1 UI
Table SA-3
Standard Applications
Expected line type parameters
are performed with the "ANT-20 TX clock from RX" setting.
pp
Measurements performed
Explanation
Yes
Yes
Yes
FAS and CRC errors are not returned to the ANT-20 via the loop
back.
Every inserted CRC-4 error must be acknowledged by an E bit
error.
Explanation
The line must return a framed all ones signal if no signal is present
at the input.
The line must return a RDI (D bit) if no signal is present at the
input.
RDI must pass through transparently.
Corresponds to an "end-to-end" delay of 11 ms
Intrinsic jitter measured with HP1 (10 Hz high-pass filter)
ANT-20 NEXT
SA-9