Selecting The T1 Pad Settings; Setting T1 Transmit Level; Setting T1 Receive Level; Solving T1 Problems - Comdial DXP Plus Manual

Troubleshooting The DXPT1 Installation
5

Selecting The T1 PAD Settings

The system pad settings that you select through the DXP Plus system programming are very important for
the correct audio level to be transmitted and received and for echo suppression.
5.1

Setting T1 Transmit Level

For the older software, set to normal (uses low, very-low, normal, high, very-high settings). For software
using Gain1, Gain2, Nominal, Loss1, Loss2, Loss3, Loss4, and Loss5, use Nominal setting.
5.2

Setting T1 Receive Level

For the older software, set to Very-Low. For the Loss/Gain software, set to Loss4. If echo problems
occur, try Loss5.
6

Solving T1 Problems

See the following table for T1 problems you could encounter and their possible causes.
Signalling bits are not being received properly
(no seize) or the network is not "seeing" the
seize.
When the T1 option is installed in a DXP
system, the DXP shows massive seizes on the
inbound channels.
The DXPT1 is seizing outward A=1 and B=1
and channel is in the idle state.
The SIG red LED on the DXPT1 board is lit
indicating no receive signal.
Bipolar alarms are indicated when T1 option is
first installed.
The SLIP red LED on the DXPT1 board is lit
indicating frame slips are occurring.
Echos are heard.
PROBLEM POSSIBLE CAUSE
Associated multiplexer (mux) equipment may
be defective if installed between the DXP and
the central office (CO).
Incorrect trunk assignments. For example,
ground start idle bits will cause seizes on DID
and E&M trunk assignments.
Channel not assigned and not disabled. All
LEDs will be off upon making a request for
trunk assignment information (see section
4.6.2).
- If new install, cabling may be reversed.
- Wiring to DXPT1 board may be defective
- DXPT1 board may be defective. Verify by
installing local loopback.
- Only one receive wire connected. Check
cable.
- Noise sources or lightning.
DXOPT-SYN card may not be locked. There
should not be any red LEDs on this card lit.
Verify presence of primary or secondary
sources by the green LEDs lit on this card.
- Two- to four-wire hybrid conversions have
been made. Cut in echo suppressors to
eliminate echos on calls over 600 miles and
inform the network.
- Pad setting may be incorrect causing
acoustical feedback (see section 5, PAD
Settings). 0 dB (or -3 dB) is recommended
for transmitted data and -9 dB at an industry
standard telephone (IST).
Throubleshooting The DXPT1 Installation – 21
IMI89–207