Comdial Dxp Plus Instructions Manual

7.7 Radio Frequency Interference
The electronic key system contains incidental radio frequency generating circuitry and, if not installed and used
properly, may cause interference to radio and television reception. This equipment has been tested and found to
comply with the limits for a Class A computing device pursuant to Subpart J of Part 15 of FCC Rules. These
limits are designed to provide reasonable protection against such interference when operated in a commercial
environment. Operation of this...

7.0 Knowing The Specifications
DXP Capacity10 T1 boards
ModesSuperframe, extended superframe
FramingD4
Channels Allocated8, 16, or 24
Industry StandardsANSI T1.403-1989
AT&T PUB 62411
Maximum Output2.4V to 3.6V base to peak, short circuit
protection to 120 mA, rms
Line Rate1.544 Mbps
Line Code
Type Bipolar AMI
Zero Suppression B7 or B8ZS selectable
Receive Sensitivity-26 dB or -36 dB selectable
Impedance100 Ohms
DXP Loss Insertion
Transmit -6 dB (selectable to 0 and -3 dB per channel)
Receive 0 dB
T1...

8.0 Defining The T1 Terms
Bipolar
A bipolar signal is composed of alternating pulses that both represent a digital logic 1. The positive pulse is a (+)
and the negative pulse is a (-). Zero volts represents a space, or digital logic 0.
Bipolar Violation (or error)
A bipolar error is a digital logic 1 (or mark) that has the same polarity as its predecessor.
NOTE: Every time the system regenerates the signal stream, it corrects any bipolar errors; therefore, it prevents
end-to-end error checking from using...

Direct Inward Dial (DID) T1 Trunk
DID is a protocol for inbound calls where the network sends the extension number during the beginning of the
call. The system supports the 0 through 7 inbound digits. The network does not translate the digits to a valid
extension—the system’s DID translation tables perform this action.
DS-0 (Digital Signal-Level Zero)
Digital Signal-Level Zero is a single 64Kbit channel inside a T1 span.
E & M T1 Trunk
E&M is a signalling protocol that supports both inbound and outbound...

Loopback Payload
The loopback payload feature is an ESF-only method of loopback which loops the network receive input path to
the remote T1 equipment’s transmit output path. This loopback method does not loop the first bit of each frame to
allow the DXPT1 board’s facility data link to continue to transmit maintenance information. You can use switches
SW2–7 and SW2–8 to manually initiate the payload loopback or you can allow the network to send an FDL
message to initiate or restore the payload loopback....

Smart-Jack (Network Interface Box)
A smart jack is a demarcation box provided by the central office. A smart jack provides isolation and increased
signal drive (up to one mile) and can respond to loopback commands for diagnostic purposes. The central office
usually provides an 8–pin modular jack for T1 equipment connection. Pin 1 of the modular jack goes to pin 1 of
the DXPT1 modular jack, and so on. Only pins 1 and 2 (DXPT1 receive), 4 and 5 (DXPT1 transmit) require
connecting.
Superframe Mode (SF)
The...

Installing The Serial Data Modem
In The DXP Plus Digital Communications System
1.1 Understanding The Modem
The serial data modem allows remote servicing and programming of the DXPPlusdigital communications
system. The DXMDM is a general-purpose, Hayes*-compatible, serial data modem that receives its operating
power and configuration programming from the DXP Plus. The modem’s operating parameters appear in the
following chart.
* Hayes is a registered trademark of Hayes Microcomputer Products
BPS Out BPS...

1.2 Installing The DXMDM Modem
The following procedure explains how to install the serial data modem. Figure 1 illustrates the relative position of
the modem and the location of its connections. The modem fits on the left side of the equipment shelf.
1. Locate DIP switch SW7 on the services board, and set it to its OFF position.
2. Insert the modem as illustrated in Figure 1.
3. Attach the modem to the equipment shelf with a single screw through the mounting-screw hole on the
modem’s front plate.
4....

SERIALStatus
PWR
Line
Power
Cord
Serial Port
Cord
PLUS014
Telephne Line Cord
Figure 1. Installing The Modem In The Main Cabinet
Equipment Shelf Serial Port Cord
Power CordTelephone Line Jack
Modem
Power Jack
Default
Modem
Communications
Jack
DIP
Switches
CPU Board
PLUS015
Figure 2. Viewing Modem Position And Connection Locations
Installing The Serial Data Modem IMI89–185
Installing The Serial Data Modem – 3 

Installing A Dual Tone Multiple Frequency (DTMF)
Receiver Card In The DXP Plus Digital Communications
System
1.0 Introducing The DTMF Receiver Card
The DXPPlusdigital communications system supports the use of on-premise industry-standard telephones.
To support the DTMF dialing of industry standard telephones, the DXP Plus services board provides on-board
DTMF receiver circuitry. This circuitry supports dialing of one industry-standard telephone at a time. This
provision is adequate, if your site requires...