Considering Pre-Installation Details - Comdial DXP Plus Manual

Troubleshooting The DXPT1 Installation
1.3

Considering Pre-Installation Details

For operation with the DXP Plus, the T1 board must be Revision B or higher. If the T1 board that you
are installing is a lower revision, contact Comdial Technical Services (1–800–366–8224) for advice
before you proceed with the installation..
If you are the installer, you must consider the following things to ensure a proper installation.
A. Determine the T1 trunk configuration and communicate this to the central office and/or the network
for coordination and assignment of service.
B. Determine whether the dial type is tone or pulse.
C. If DID or E&M protocols are going to be used, determine the number of DTMF receivers needed.
D. If the above protocols are used, coordinate the blocks of numbers assigned with the data base.
E. For DID and E & M protocols, determine the type. Wink start, delay dial, or immediate start are
available. Wink start is very popular. If you choose immediate start inbound, select dial pulse over
tone dial to ensure that the DXP has enough time to react.
F. AT&T will not supply dial tone unless the customer ordered this feature. However, if you enable the
automatic route selection (ARS) feature, it will supply dial tone.
G. Configure an interface cable (8-conductor cable terminated with modular jacks) to connect to the
DXPT1. See section 4 in Installing The DXPT1 Digital Carrier Transmission Option, IMI89–193 for
more instructions. Pins 7 and 8 must be open at the DXP Plus end for DXPT1 Issue 2 while Issue 3
boards and above will not require pins 7 and 8 to be open. A smart-jack often connects pins 7 and 8 to
chassis ground. If the chassis ground is connected at the smart-jack, the DXP Plus receive will most
likely show loss of signal. (Pins 1 and 2 are shorted to 7 and 8 to allow for an inverted cable to be
used.)
H. Order spare boards, if needed.
I. Make sure you have a synchronization card to install on the auxiliary board.
J. Determine the optimum DXPT1 board configuration. If a T1 board occupies a universal slot, more
stations are possible than by using analog trunk boards.
K. If fractional T1 is being considered, decide whether 8-, 16-, or 24-channel mode is most beneficial.
L. Verify that primary lightning protection (such as gas discharge tubes) is provided where the T1
copper wires enter the building. This should be the case when a smart jack is installed by the central
office. Primary protection is a must since the DXPT1 contains only secondary protection.
M. For a DXP-to-DXP application, where no outside network exists, only one synchronization card is
required. The designated "master" DXP Plus does not require a synchronization card.
CAUTION
Throubleshooting The DXPT1 Installation – 7
IMI89–207