Maintenance-Object Repair Procedures
555-233-143
8-666 Issue 1 May 2002
DS1 CONV-1 and DS1 CONV-2 Line
Compensation
The DS1 facility line signal is pre-equalized at the transmitter on the DS1 CONV
circuit pack so that DS1 line pulses have correct amplitude and shape when they
reach the Network Interface (see Figure 8-25 on page 8-675). The amount of
equalization necessary is determined by the distance to the Network Interface and
also by the type of wiring used to connect to the Network Interface. If the
equalization is not set to the correct value, potentially high error rates (errored
seconds) will be observed on the DS1 facility. Equalization values are determined
as follows:
Line compensation is applicable only to T1 operation, thus these fields will not
appear on the fiber-link form if the TN1654 DS1 CONV is administered for a bit
rate of 2.048 Mbps.
Line Coding
This field is used to administer the line coding for the DS1 facility. For the TN574
board and the TN1654 board in T1 mode, the field may be set to ami-zcs or b8zs.
If the TN1654 board is set for E1 operation, the line coding may be set to either
ami-basic or hdb3. The line coding must be the same at each end of the DS1
CONV complex.
Framing Mode
Either esf or d4 framing mode can be selected for the DS1 facility. The same
framing mode must be used at each end of the DS1 CONV complex.
For TN574 DS1 CONV boards, the Framing Mode field is administrable.
For TN1654 DS1 CONV boards, this field is display only. It cannot be
administered. The TN1654 has option switches located on the component side of
the circuit pack. If T1 operation is selected via the first switch, four additional
switches are used to select the framing mode for each facility. Each facility can be
set to either D4 or ESF framing. The Framing Mode field will display what the
switch is set to for the DS1 facility.
Framing Mode is applicable only to T1 operation, thus this field will not appear on
the fiber-link form if the TN1654 DS1 CONV is administered for a bit rate of
2.048 Mbps.
Equalizer
Setting
Distance to Network Interface (feet)
Cable type 22 AWG ABAM &
24 AWG PDS Cable type 26 AWG PDS
1 1 to 133 0 to 90
2 133 to 266 90 to 180
3 266 to 399 180 to 270
4 399 to 533 270 to 360
5 533 to 655 360 to 450
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