Comdial Dxp Plus Instructions Manual

							Services Board
Status
Red
Yellow
Sync
Signal
Blue
Bipolar
CRC
Slip
Unlock
B8ZS/COFA
Remote Loopback
Local Loopback
Payload Loopback Primary
Secondary
Unlocked
Status
Manual
DXOPT-SYN
Card
Diagnostic Switches
and LEDsDXPT1 Board
PLUS007d.cdr
Viewing The Alarms And Indicators
Installing And Programming The DXPRI Card IMI89–255
Viewing The Alarms And Indicators – 35 
						

							Defining The T1/PRI 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 bipolar errors.
B8ZS (Binary Eight Zero Substitution)
This is a technique to send an all-zero channel without violating the ones-density requirement (a single one in
each channel and no more than 15 zeros in a row). Voice transmission will not allow an all zero channel. The
system accomplishes B8ZS suppression by inserting a special bipolar error that is interpreted, not as an error, but
an all zero channel. The B8ZS feature replaces the all-zero channel two different ways. The feature replaces the
all-zero channel with the sequence 000 + - 0 - + if the preceding pulse was a +, and the feature replaces the
all-zero channel with the sequence 000 - + 0 + - if the preceding pulse was -. The + represents a positive pulse,
the - represents a negative pulse, and 0 represents no pulse. The B8ZS feature is standard with ISDN–PRI
service.
CAS (Channel Associated Signalling)
Channel Associated Signalling is a method of signalling where all signalling occurs on the channel being
controlled. Examples of CAS are loop start and T1 lines.
CCS (Common Channel Signalling)
Common Channel Signalling is a method of signalling were all signalling for a group of channels occurs on one
channel. ISDN is a CCS protocol.
COFA (Change of Frame Alignment)
When switch SW2-6 is off, the green LED on the DXPT1 indicates whether the network source or the network
span caused the last frame synchronization. (This indication disregards the first re-sync at cold start or a system
reset —cold start and reset causes the network source to re-sync.) A COFA occurs if the network source does a
re-sync. The COFA is a diagnostic tool that identifies the source of the loss of frame synchronization.
CPE/Carrier Equipment
The DXPT1 is normally classified as Customer Premise Equipment (CPE). If you use SW2–2 to configure the
DXPT1 board to use the internal CSU, the network may require that the system be classified as Carrier Equipment
(CE). The information packet that the T1/PRI board sends to the network contains a facility data link (FDL)
maintenance message that has a bit in it that provides this identification.
CRC (Cyclic Redundancy Check)
A method of checking errors from the transmission source to the destination. For T1/PRI operation, CRC
calculates a checksum depending on the data in a frame. (You must enable CRC with DIP switch SW2-4).
IMI89–255 Installing And Programming The DXPRI Card
36 – Defining The T1/PRI Terms 
						

							DS-0 (Digital Signal-Level Zero)
Digital Signal-Level Zero is a single 64Kbit channel inside a T1/PRI span.
Extended Super-frame Mode (ESF)
Extended Super-frame Mode consists of 24 frames. The frame bit uses only 6 frames leaving 18 bits for other
purposes. These spare 18 bits provide 6 bits for CRC information and 12 bits for a facility data link. The facility
data link is for maintenance information (as defined by the ANSI T1.403 specification). Like the super-frame
mode, the 64–Kbit user channels have 24 frames available for use.ESF is standard with ISDN–PRI service.
FDL (Facility Data Link)
The Facility Data Link is a 4–Kbit communication link from the network to the T1/PRI board. The system sends
preemptive messages (for example, yellow alarm and loop back), if needed, and sends error packets to the
network once a second. The packets contain alarm history in accordance with the ANSI T1.403 specification.
FDL is standard with ISDN–PRI service.
In band Signalling
A signalling method where the system sends overhead signalling along with channel traffic.
Loop-back Local
An operation method that loops the T1/PRI board’s transmit output and receive input paths. The loop back
terminates all traffic and halts call processing. While in this idle condition, the system continues to transmit the
T1/PRI transmit stream to the network but it will not answer incoming calls. If the remote T1/PRI equipment is
the clock source (primary or secondary) for the DXOPT-SYN card, the remote equipment terminates the reference
signal because the network receive circuit is open in local loop back. You initiate local loop back by setting the
appropriate SW1 switches. The main purpose of local loop back is to verify the T1/PRI board’s ability to
synchronize properly.
Loop-back Payload
The loop back payload feature is an ESF method of loop back which loops the network receive input path to the
remote T1/PRI equipment’s transmit output path. This loop back method does not loop the first bit of each frame
to allow the T1/PRI 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 loop back or you can allow the network to send an
FDL message to initiate or restore the payload loop back. The T1/PRI board goes out-of-service during the loop
back time.
Loop-back Remote
The loop back remote feature loops the network receive input path to the remote T1/PRI equipment’s transmit
output path. The remote loop back feature terminates all traffic and halt any call processing. You can use the
SW2 switches to manually initiate remote loop back or you can allow the network to remotely initiate the
condition. The T1/PRI board’s facility data link, or maintenance channel, can enable and disable remote loop back
automatically or you can set SW2–7 on and SW2–8 off to manually enable remote loop back or set both switches
off to manually disable the feature.
Installing And Programming The DXPRI Card IMI89–255
Defining The T1/PRI Terms – 37 
						

							LIU Line Interface Unit
The line interface unit is the interface between the copper wires and the T1/PRI board’s framing circuitry. The
LIU is responsible for separating the 1.544MHZ receive clock from the incoming stream and converting bipolar
Alternate Mark Inversion (AMI) to 5–volt digital logic. The LIU also supports the automatic line build-out that
regulates the transmit level according to the receive strength (LIU-2 switch).
Primary Clock Reference
The straps on the DXSRV–PLS board designate the primary clock reference. Primary clock reference is the first
choice reference clock used to synchronize the DXP Plus to the incoming span. If the system looses
synchronization, it uses its secondary clock reference.  If the secondary clock reference is not available, the
DXOPT-SYN card’s variable clock oscillator (VCO) switches to the fixed oscillator on the DXCPU (cpu) board.
When it does this, slips occur.
Repeater
A repeater is a amplifying device that central office technicians place at approximately one mile intervals along a
T1/PRI circuit to boost the T1/PRI signal. The T1/PRI specifications allow a maximum of 50 repeaters along a
communications path.
Slip
This term describes the condition that exists when the transmit 1.544 MHz clock is different from the receive
1.544 MHz clock. When the system collects or looses a frame of information due to the span frequencies being
different, the system generates a slip error. Slip does not affect voice transmissions and may not affect modem
traffic; however slip does effect digital data traffic. The T1/PRI board does not currently support digital data
traffic. Also, at times a central office takes a T1/PRI span out of service if too many slips occur—one or two a
day is permissible (the carrier supplier will furnish you with an an exact number if you request that information
from them).
IMI89–255 Installing And Programming The DXPRI Card
38 – Defining The T1/PRI Terms 
						

							Knowing The T1/PRI Specifications
Capacity10 T1/PRI boards
ModesSuper-frame, extended super-frame
FramingD4
Channels Allocated24
Industry StandardsANSI T1.403-1989
AT&T PUB 62411
CCITT 0.921
CCITT 0.931
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 B8ZS
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
ConnectorRJ48C, miniature 8-position, shielded
(per ANSI T1-403, 1989)
CableUp to 6,000 feet between DXPs, 22 AWG,
twisted-pair, no external components
CSU FunctionBuilt-in; CPE or CARRIER selectable
Transmit Attenuation
Manual 0, -7.5, -15, or -22.5 dB selectable
Automatic DefaultInput Jitter Tolerance138 UI @ 1 Hz; 0.4 UI @ 10 KHz—100 KHz
(0 dB line); corner frequency = 6 Hz (attenuates
20 dB per decade above corner)
Surge Protection1 AMP fuse and transient protection for metallic
>6 volts P-P; Longitudinal (tip—ring and chassis
ground) protection 1500 volts minimum.
Elastic StoreTwo frames, no frame loss when slipping
ComplianceFCC Part 68/Doc
FCC Part 15
UL-1489/CSA (safety)
USOC = 6.0Y
FIC = 04DU9–1SN
Yellow Alarm Type
Alternating bytes = all zeros and all ones;
(prohibiting ANSI FDL messaging during
yellow alarms is selectable)
Clocking
Synchronization Slave mode from DXOPT-SYN card on
Auxiliary board
Min. RX Freq. Capture 1.544 MHz±200 Hz, T1 board;
16.384 MHz±2048 Hz, Sync card
TX Master Mode Freq. 1.544 MHz±75 Hz
Loop back Modes
Extended Super-frame Mode Local, remote, payload loop back (manual)
FDL ANSI network remote loop back
FDL ANSI network payload loop back
LED Alarms/ErrorsStatus
Red Alarm
Yellow Alarm
Blue Alarm
Loss of receive synchronization
Loss of signal
Bipolar error(s)
CRC errors (ESF)
Slip errors
Phase Lock error
Installing And Programming The DXPRI Card IMI89–255
Knowing The T1/PRI Specifications – 39 
						

							Up-Grading Your DXPT1 Board For ISDN–PRI Support
Up-grading existing revision B or later DXPT1 boards for ISDN–PRI service consists of adding a DXPRI card to
the T1 board, and changing the board’s chip firmware. When you do this, the T1 board/DXPRI card combination
with the new firmware becomes a DXPT1–PRI board.
If you add the ISDN–PRI firmware to an existing T1 board but do not install the DXPRI card, you create a NFAS
(Network Facility Associated Signalling) DXPT1–NFAS board. The NFAS boards are slaves to the master
DXPT1–PRI board in multiboard installations.
Installing The DXPRI Card
1. Be sure you are standing on the conductive mat that you have placed in front of the cabinet area and grounded
to a good earth ground. (The third wire ground of the AC power line is an acceptable grounding point if the
AC wall jack is properly grounded.) The grounded conductive mat provides a safe static electric discharge
path.
2. Install your static discharge wrist strap on your bare wrist; adjust it for a snug fit. Be sure that the strap is not
isolated by clothing. Connect the wrist strap cord between the wrist strap and an AC or earth ground.
NOTE: With the common equipment in the installed position, the ground lug on the side of the cabinet is an
appropriate grounding point since it should have a heavy ground wire connected between it and a good
earth ground.
3. Normally you should disconnect the AC power cord from the AC outlet and disconnect the optional battery
back-up assembly from the digital communications system’s main cabinet power supply; however, when
necessary, you can remove a DXPT1 board from an operating system. If you must do this, connect one end of
a standard telephone handset coil cord to the pre-charge port on the power supply. During step 5, you will
connect the other end of this coil cord to the pre-charge jack on the T1 board.
4. Loosen the retaining hardware and lift the front panel away from the common equipment cabinet.
5. Locate the DXPT1 board, and if you are removing the board from an operating system, connect the free end
of the pre-charge cord that you installed in step 3 to the pre-charge jack on the line board.
6. Loosen any retaining hardware, use the extractor levers to disconnect the board from the connector on
cabinet’s backplane, and slide the board free of the board cage. If you connected a handset cord between the
pre-charge port on DXPPluspower supply and the jack on board (as directed in step 4), disconnect it after
removing the board.
7. Place the board in a static protection bag for safe keeping, and transport it to a static safe work area.
8. At the static safe work area, with your wrist strap in place, remove the DXPT1 board and the DXPRI card
from their static protection bags.
7. Referring to the illustrations on the next page, orient the DXPT1 board and the DXPRI card, and attach them
with the supplied hardware.
IMI89–255 Installing And Programming The DXPRI Card
40 – Up-Grading Your DXPT1 Board For ISDN–PRI Support 
						

							Replacing The Firmware
1. With the DXPT1 board still at your static-safe work area and with your static discharge wrist strap on your
bare wrist and properly grounded, replace the chip-set firmware with the ISDN–PRI firmware.
2. Locate the current chip firmware (U5 at the upper rear of the board—see the illustration), and note its
orientation in its socket.
3. Use a chip extraction tool to lift the chip free from its socket.
4. Remove the replacement chip from its static protection bag and orient it to match the orientation of the chip
that you just removed.
5. Press the chip into place in the socket.
CAUTION
Do not bend any of the chip’s pins so that they do not make contact with the socket.
6. Inspect the modified DXPT1 board for proper installation, and return it to its static protection bag.
7. Refer to the paragraph titled,Installing The T1/PRI Line Board, and re-install the  modified DXPT1 board in
the system.
8. Store your old firmware in a static-safe environment in the event that you may need it in the future.
DXPT1
Board
DXPRI Card
ISDN2.cdr
Firmware
Location
(Chip U5)
Installing The DXPRI Card And ISDN–PRI Firmware
Installing And Programming The DXPRI Card IMI89–255
Up-Grading Your DXPT1 Board For ISDN–PRI Support – 41 
						

							DP. I I I I . .
and
FX SeriesDigital Communications Systems
Understanding The
Visual Man-Machine Interface
COMDlA” 
						

							Table of ContentsIntroducing VMMI........................
1Using the Programming Screens....................
1
Using On-Line Help........................2
Obtaining a Printout Record......................2
Using the Computer Mouse.....................3
Determining Your Equipment Needs..................
3
Connecting a PC to the
Digital Communications System..................
4Connecting a PC to the DXP Plus...................
4Connecting a PC to the DXP....................
5
Connecting Cabling For FX Series...................
6Installing the VMMI Program
and Help Software 
-.......,...............7Loading 
VMMI With Windows 3.1...................7
Loading VMMI With Windows 95....................7Making the Programming Connection...............
8
Using VMMI Software toArchive and Restore the Database.................
9Using VMMI Software to Build a New Database..........
Up-Grading the System Software on the DXP Plus.........
Activating System Software on the FX Series...........
Turning On the FX Series System Software..............
Completing the FX Series System Start-Up Procedure..........
Up-Grading The System Software on the DXP...........
Converting the DXP Database....................
Installing the RAM Card and Software Card in the DXP..........
Master Ciearing The DXP System..................
Restoring the Comverted Database to the DXP.............
Translating The DXP Database...................
10
11
12
13
14
15
15
1620
2122
Table of Contents - iii 
						

							GCA40-182Understanding the VMMlIntroducing 
VMMI
Using The Programming ScreensVMMI is a Microsoft* Windows based programming method that is menu-driven and allows you to enter
choices in dialog boxes. The VMMI programming index is expandable much like the file manager on a
computer’s operating system software. As you use your computer mouse to move the screen cursor to the
desired location, and double-click the mouse button on a main menu element, it expands to show sub-menus
that, in turn, open at a click to show a particular programming area. A double-click on a main element
collapses its expanded menu.
VMMI allows you to directly connect to the communications system and program it on-line. Alternately,
you can program a database off-line, save it, and down-load it in the communications system at a later date,
When you make programming changes on some of the VMMI menus, note that the program places a 
+K to
the right of a changed item to denote that you have altered the setting from its previous value. Once you
click on either the Apply button or the Undo Page or Undo All buttons, the program removes the 
4~ and either
applies the new value or returns to the original value.
*Microsoft Windows is a registered trademark of Microsoft Corporation, Redmond Washington.
Introducing 
VMMI - I