VRS Fixed Message

VRS Fixed Message 02 General Message Number Input Data 0 = Disable (VRS fixed message will not be played.) 1 = Enable (VRS fixed message will be played.) 0 ~ 100 (0 = No General Message Service) Description Enable (1) or disable (0) the system ability to play the fixed VRS messages (such as You have a message). This item assigns the VRS message number to use for the General Message. Default 0 Related Program 0 03 04 05 06 07 08 VRS No Answer Destination VRS No Answer Time Park and Page Repeat Timer (VRS Msg Resend) Set VRS Message for Private Call Refuse (VRS Msg Private Call) Set VRS Message for Caller ID Refuse (VRS Msg CID) Call Attendant Busy Message 0 ~ 25 (Incoming Ring Group Number) 0 ~ 64800 seconds 0 ~ 64800 seconds 0 = No Message Played 1 ~ 100 = VRS Message 1 ~ 100 101 = VRS Fixed message (Message will only play if PRG 40-10-01 is enabled.) 0 = No Message Played 1 ~ 100 = VRS Message 1 ~ 100 101 = VRS Fixed message (Message will only play if PRG 40-10-01 is enabled.) 0 ~ 100 (0 = No message) This item assigns the transferred Ring Group when the VRS is unanswered after Call Forwarding with Personal Greeting Message. If an extension has Personal Greeting enabled and all VRS ports are busy, a DIL or DISA call to the extension waits this time for a VRS port to become free. If a Park and Page is not picked up during this time, the Paging announcement repeats. This item assigns the VRS Message number to be used as Private Call Refuse. When Fixed message is set, VRS message guidance is: “Your call cannot go through.” This item assigns the VRS Message number to be used as Caller ID Refuse. When Fixed Message is set, VRS message guidance is: “Your call cannot go through.” 0 (No Setting) 0 0 0 0 0

ucd group member

While  a caller waits for a UCD group  member  to answer (in queue),  several  queued call operations are possible.   These  include the  following. •   No Answer – Member  advancement.  Each UCD  group has a No  Answer  Timer.   You can set this timer to  advance the call from one UCD group member to the next when the ringing  member does not answer  the call  within the  time allotted. •   Overflow  1 Destination programming.  Each  UCD  group has  an overflow 1 timer and destination.   You can set this timer  to determine how long calls  will  remain in queue,  before being routed  to the  overflow 1 destination.  The destination can  be an extension  responsible for handling  calls that  remain in  queue too long, or a voice  announcement device.  You  can use recorded announcement devices  to  play recorded messages  to callers  waiting in queue, for example, “All agents are still  busy  - please continue to hold.”   The system  plays the overflow  1  destination only once.   For high  traffic  scenarios,  you can  use  a  recorded voice announcement UCD group to play the  same  message to multiple callers. •   Overflow  2 Destination programming.  Each  UCD  group has  an overflow 2 timer and destination.   You can set this timer  to determine how long calls  will  remain  in queue, following  the overflow 1 timer, before being routed  to the overflow  2  destination (overflow 1  timer + overflow  1 destination recorded message time + overflow 2  timer.)   The destination can be  an  extension responsible for handling calls that remain in queue too long or a voice announcement device.   You can use  recorded announcement devices to  play  recorded  messages to  callers waiting in queue, for example, “Please continue  to hold to  reserve  your place in  queue.”   For high  traffic scenarios, you can use a recorded voice  announcement UCD  group to play  the same message to multiple callers. •   Overflow Count  programming.  Each UCD group has an overflow  count that is  associated with the  overflow 2 timer.   You can set  this timer to  allow a specific number  of times  that the  system may repeat the  overflow  2 timer.  For each cycle  of  the overflow 2 timer, the  system plays the overflow 2 destination  recording.   If a call  remains in queue so  long that the overflow count counter expires,  the system routes  this  call to the programmed  reroute  destination. •   Reroute Destination programming.   Each  UCD  Group has a reroute  destination.   You can program this  with an  extension number the system uses  to remove  the call from UCD  group queue.   The system  then routes the  call for immediate handling. Other features whose  programming may affect  UCD programming  includes the following. •   CO Line Ring  Assignment •   UCD Reroute  Destination •   UCD Voice Announce Group •   UCD Agent Log On/Log  Off •   Voice Mail -  Digital Integration •   Recorded  Announcement Devices (RADs)

Delimiter Dial Code

Receive Format Delimiter Dial Code Route Setup of Receive Dial 0 = Address 1 = *  ANI 2 = * *  DNIS 3 = *  ANI * *  Address 4 = 5 = ( *  ANI *  DNIS *  DNIS *  ANI *  = Delimiter Code) 1 ~ 9, 0, #, * 0 = Fixed Route (Item 08) (No Routing) 1 = Routes on Received DNIS or Address Data 2 = Routes on Received ANI Data COS 01 = 0 COS 02 ~ 15 = 0 * * * Use this option to specify the format of the ANI/DNIS data received from the Telco. Make sure your entry is compatible with the service the Telco provides. The character *  indicates a delimiter.If Program 34-01-02 is selected to 2 (MF), this Program works only as 4 = *ANI *DNIS *. This option defines the character Telco uses as a delimiter (see entries 1 ~ 5 in Item 1 above). Valid entries are 0 ~ 9, #, and *. This option specifies the source of the data the system uses to route incoming ANI/DNIS calls. If option  2  is selected, refer to Program 34-09-04

fax machine

1. Place line  4 (743) into CO group2  (800). 2. From the Fax machine,  go  off hook  and  dial 800  (be sure you are  accessing line 4).  Then  dial  a valid number.   You must  dial out on that line /(line group)  before programming the hot line (dial 740 for line 1, 741 for  line 2, 742  for line 3 etc.…). 3. Program a  System  Speed dial bin  with  a  pause.  To  do  this,  you can  use  PCDBA or  program using the  phone. Using PCDBA Go  to the DX80  PC-DBA System  Resource SPD.   No.   Programming Tenant 1screen   in PCDBA.  Choose a system speed  dial bin (DIR#s 500-699), and insert a P  for pause in its SPD.  No.  field.

Mirrored Memory Module

60-Key  Expansion  Console,  B.3,  I.8,  I.9 60-Key  Second Expansion  Console,  B.3,  I.8,  I.9 Analog ports,  I.7 Battery.  See  Cautions Cabinets Expansion, F.2 Cautions, E.1 Battery, E.1 Fuse,  E.1 Power supply,  E.1 CO  lines Capacities.  See  System  capacities Connecting, I.5 Console,  B.3,  I.8, I.9 ESI  Cordless  Handsets.  See  Phones ESI  Presence Management,  D.1 Expansion Cabinet,  F.2 Expansion Console,  B.3,  I.8, I.9 Fuse.  See  Cautions Grounding, F.2,  I.1,  I.3 Hardware  installation,  E.2–F.15 LED functions,  F.15, G.6,  H.6 Main  board,  A.2 Memory  Module, A.3 Installation  or  replacement,  F.5–F.8,  G.5,  H.5 Mirrored Memory  Module  (M3), A.3 Installation, F.9–F.13 MOH,  I.3 NSP  (Network  Services  Processor),  A.7 Overlays,  B.4 Paging, I.4 Phones Digital  Feature  Phones,  B.1 ESI  Cordless  Handsets,  B.2,  B.3 IP  Phones,  B.2 VIP  Softphone,  B.4 Port  cards Capacities, A.4 Charts, I.13–I.20 Installation, G.3–G.4,  G.3–G.4 Installation, F.2 Port  card  adapter,  F.3 Power,  I.1 Power  Distribution Shelf,  A.3 Power supply.  See  Cautions Transformers, wall-mount,  A.3 PRI, I.5 Regulatory  information  (U.S. and Canada),  E.2 Ringer  equivalence number  (REN),  E.2 Serial  ports,  I.3 Site location,  F.1 SMDR, I.3 System  capacities,  D.1 T1, I.5 UPS (uninterruptible  power  supply),  I.1 VIP  Softphone.

programming password setup

Programming Password Setup  to set the system passwords. For password entry, the system allows eight users to be defined. Each user can have a: • Unique alphanumeric name (up to 10 alphanumeric characters) • Password entry of up to eight digits (using 0 ~ 9, # and • Password level *) The IN level password is used by the System Installer for system programming. The SA or SB level password cannot access the IN level programs. The reverse type (white on black) just beneath the Description heading is the program access level. You can only use the program if your access level meets or exceeds the level the program requires. (SA level password can access to SA or SB programs, and SB level password can access to SB programs only.

Registration Expire Timer

Registration Expire Timer Input Data 60 ~ 65535 seconds Description The Expires value of the REGISTER message which received from DR700 terminal is out of range or when the Expire value is not set up, in case it assigns the effective time to the DR700 terminal. The timer for supervising whether DR700 terminal is connected or not. Default 180 02 03 04 05 06 07 08 09 Subscribe Expire Timer 60 ~ 65535 seconds Session Expire Timer 60 ~ 65535 seconds Minimum Session Expire Timer Invite Expire Timer Signal Type of Service Error Display Timer Digest Authorization Registration Expire Timer 60 ~ 65535 seconds 60 ~ 65535 seconds 0x00 ~ 0xFF (0 ~ 9, A ~ F) 0 ~ 65535 seconds 0 ~ 4294967295 seconds Temporally Password Read Only: Maximum 16 characters (0 ~ 9, a ~ f, A ~ F) The subscribe Expire timer to transmit and receive the terminal operation instructions between the Main Device and DR700 terminal. Set effective time for supervising the Voice Path. Set minimum value of effective time for supervising the Voice Path. Set effective time for Incoming/Outgoing call when the Expire value is not set in the INVITE message received from DR700 terminal. Set Type of Service value which applied to send SIP Message Pac

initialize

1  System  parameters 11   Initialize 12   Installer  password 13   Administrator  password 14   System clock 141   Set  time/date 142   Automatic  time  setting 143   Clock  adjustment 15   System  timing  parameters 151   Flash duration 152  Transfer  forward  timer 153   Recall  timers 1531   Exclusive hold 1532   System  hold 1533   Hold  recall  rings 154   ACD timers 1541   ACD exit  timer 1542   ACD wrap  timer 1543   ACD  hold recall  timer 155   ACD wrap  timer 156   Cell  phone delay 157   Device  timers 158   VIP Attendant  exit  timer 16   System  feature  parameters 161   Recording  alert  tone 162   Connect  tone 163   Station feature  set activation 164   Esi-Link  location  no./line  group  access  selection 165   Auto  attendant parameters 166   CO  line  parameters 167   Voice  mail parameters 169   Feature  set activation 17   System speed-dial 18   Maintenance/SMDR  serial  port 2  CO  line programming 21   Line  programming 211   Analog  CO  line  programming 212   T1  programming 2121   CO line  programming 2122   T1  frame format  and  line  coding 2123   Line  build-out 2124   CSU  emulation   213   PRI  programming 2131   CO line  programming 2132   Line  build-out 2133   CSU  emulation 2134   Switch  protocol 2135   DID 214   SIP  trunk  programming 2141   SIP  trunk  programming  day/night  mode 2142   SIP  account programming 2145   SIP  pilot table programming 22   Translation  table  programming 221   Centrex/PBX  access  code   222  Toll  restriction  exception  tables   223   ARS  (Automatic  Route  Selection) 224   DID and DNIS/ANI  translation table 225   PRI  pilot number  translation table 226   Local  allow  table 23  Line  parameters 231   Line  receive  volume 232   Analog  line disconnect 233   T1  line  receive  volume 234   PRI  line  receive  volume 24   Caller  ID  programming 3   Extension programming 31   Extension definition  and  routing 32   Extension feature authorization 321   Standard  feature  authorization 322   Advanced  feature  authorization 33   Department  programming 331   Department  definition  and routing 332   VIP ACD  parameters 34   Dial  plan  assignment 341   Flexible  number  assignment 342   Network  numbering 35   Extension button  mapping 37   ESI device  programming 371   Access  schedules 372   RFID  tag programming 373   View RFID  tag numbers 374   ESI  Presence  Management  parameters 375   ESI  Presence  Management  Reader  parameters 30   Station  move1 4   Auto  attendant  programming 41   Auto attendant  branch  programming 42   Announce  extension number 43   Automatic  day/night  mode  table 5  Voice mail programming 51   Maximum message/recording length 52   Message purge control 53   Guest/info mailboxes 54   Group  mailboxes 55   Message notification  options 551   Station delivery  options 552   Delivery/paging  parameters 56   Cascade notification  mailboxes 57   Q  &  A  mailboxes 58   Move and  delete  messages 6  Recording 61   Record  system  prompts 62   Record  directory  names 63   MOH programming 631   MOH source 632   Record  MOH   633   MOH volume 7   Reports 71   System  reports 711  Programming  report 712   Diagnostic  reports 72   ESI  Presence Management  access  door  report 73   ACD department  detail  report 74   Voice  mail  statistics  report 75   System speed-dial  list 76   NDDS  report 8   IP  programming 81   Display  licenses 82   Local  programming 821   IP  programming 822   Local  phone starting  address 824   Network  Services  Processor 83   Esi-Link  programming 831   Local  location  number 832   Esi-Link  location  programming 833   Delete  Esi-Link  location 834   Esi-Link  publish  list programming 835   Compression  algorithm 84   ESI  SIP Card  programming 85   ESI ASC  programming 86  ESI Mobile Messaging selection

LED functions

LED  functions The unit's  various LEDs  are designed to  provide visual  feedback as  follows: Power LED The  Power  LED  is  located  on  the  right side  of  the  Base  Cabinet, and  is  illuminated  when  power is  being applied to  the system.  This  LED blinks  periodically to  indicate  that  the main  processor  is  operational. Port  LEDs The  Port  LEDs  are located  above their  respective  connectors  on  each  installed port  card.  Each  LED is illuminated  when  any  port on  its  associated  port card  is  in  use.  Note:  Disconnecting a  connector  when its  respective  LED  is  lit  will disconnect  any  of  its  ports  that  are in use. Upon  power-up,  approximately five minutes  are required  for  the system  to  configure.  The  Power  and  Port LEDs  will  blink three times to  indicate  that  the power-up  sequence has been  completed.  Note:  When the LED  on a DLC1  is  . .  . •    .  . . blinking, the  T1/PRI  circuit is  out  of  service. •    .  . . not  lit  at  all,  the  T1/PRI  circuit is  in  service  but  is  idle. •    .  .  .  lit  solidly,  the  T1/PRI  circuit  and/or  a  station on the  card  are  in use. ESI  Presence Management installation For information on installing ESI Presence Management, see its Installation Manu

G.711

Number of G.711 Audio Frame 02 G.711 Silence Detection (VAD) Mode Input Data 1 = 10 ms 2 = 20 ms 3 = 30 ms 4 = 40 ms 0 = Disable 1 = Enable Description Maximum number of G711 Audio Frames. When the voice is encoded using the PCM (Pulse Code Modulation) method, a unit is a frame of 10ms. Select whether to compress silence with G.711. When there is silence, the RTP packet is not sent. Default 2 Related Program 0 03 04 05 06 07 08 09 10 11 12 14 G.711 Type G.711 Jitter Buffer - Minimum G.711 Jitter Buffer - Minimum G.711 Jitter Buffer - Maximum G.729 Audio Frame G.729 Silence Compression (VAD) Mode G.729 Jitter Buffer - Minimum G.729 Jitter Buffer - Standard G.729 Jitter Buffer - Maximum Number of G.723 Audio Frame G.723 Jitter Buffer - Minimum 0 = A-law 1 = μ-law 0 ~ 255 ms 0 ~ 255 ms 0 ~ 255 ms 1 ~ 6 (1 = 10 ms, 2 = 20 ms, etc.) 0 = Disable 1 = Enable 0 ~ 300 ms 0 ~ 300 ms 0 ~ 300 ms 1 = 30 msec 2 = 60 msec 0 ~ 300 ms Set the type of G.711. Set the minimum value of the G.711 Jitter Buffer. Set the average value of the G.711 Jitter Buffer. Set the maximum value of the G. 711 Jitter Buffer. Maximum number of G729 Audio Frames. G.729 assumes the audio signal made by a specimen by 8 kHz and the frame of 10 ms is assumed to be a unit to 8 kbps by the encoding compressed method. Select whether to compress silence with G.729. When there is silence, the RTP packet is not sent. Set the minimum value of the Jitter Buffer of G.729 is set. Jitter is the variation in the time between packets arriving and the buffer allows this variation to be absorbed. Set the average G.729 Jitter Buffer. Set the maximum G.729 Jitter Buffer. Maximum number of the G.723 Audio Frame. Set the minimum value of the G.723 Jitter Buffer.

Bounce Protect Time

Bounce Protect Time 0 = No setting 1 ~ 15 = 100 ms ~ 1.5 sec Description Specify a time for detection of a valid offHook indication that is long enough to prevent an unintentional bounce of the receiver from being detected as a new Off-Hook indication from a Single Line Telephone. Default 3 (300 ms) 02 03 HookFlash Start Time 0 = 40 ms 1 ~ 15 = 90 ms ~ 790 ms HookFlash End Time 0 = HST + 0 ms 1 ~ 15 = HST + 100 ms ~ HST + 1500 ms (HST = Hookflash Start Time) Conditions None Specify the minimum hookflash time from a Single Line Telephone or analog Voice Mail system before it is detected as the beginning of a valid hookflash. Specify the maximum hookflash duration from a Single Line Telephone to receive a second dial tone.

remote connection

Remote connection to  the  DX-80 system is possible via  modem.   The optional modem may be  purchased allowing remote administration of the  DX-80 system database  and maintenance operations.  The  default directory  number of  the  modem is  199.   Some  working  knowledge of  modem operation and connection is useful. 3.5.4.11  F10-RS232C This  function key is used to  setup  the PC  COM port.  To  successfully setup the PC COM  port you  must know  how the PC hardware is configured.   In this utility  you must select  the COM Port number (PCDBA supports COM 1 or 2 only) and the baud rate that  will be used for the connection.  At default PCDBA  is setup to  use COM Port  1  at 9600  bps.  (9600  bps matches the  default  baud rate set for  the  DX80 CPM – PC-DBA Port.) While using a modem connection, it  is  best to  set the  COM port baud  rate at 2400  bps since this is the speed of the  DX-80 optional modem; setting this speed can expedite the modem negotiation  process since compression  link choices will not  be attempted.

System Maintenance Maintaining

System Maintenance Maintaining the  Comdial DX-80 digital telephone system is a combination of customer database changes,  facilities and apparatus moves, adds  and  changes.  These requirements are accomplished by practicing the  techniques, illustrations  and step-by-step instructions listed in the previous sections of this manual. When properly installed,   the  Comdial DX-80  is relatively maintenance-free.   From time to time the digital  telephone instruments may  become  dirty or dusty  and require cleaning.   We  suggest the use  of  a clean,  dry cotton (or other  soft,  absorbent) cloth  to  wipe the instrument  clean.  The use  of  chemicals to clean the telephone  plastics  is NOT recommended  since  some  chemicals  can cause permanent  damage to the telephone finish.  If deep  soiling conditions exist, many specialized telephone cleaning solutions  will provide satisfactory results.    When trying  any cleaner for  the first time, apply  the cleaner  to a small  sample area on  the underside of the instrument.   If the expected  results  are  achieved, proceed with cleaning  the remainder of  the telephone.

Serial cable

Connecting a Serial Cable for SMDR SMDR (Station Message  Detail Recording)  can be output from  the DX-80  system  for use with serial printers of  collection in call accounting devices. Connection  of the SMDR  device to  the DX-80 is accomplished  through the  serial data port on  the CPM  labeled “SMDR.” Connection  to  serial printers may  require customization  of  the  serial cable used  to make the  connection. CPM“SMDR” serial port connector (straight- (Dedicated means that this AC outlet has no other equipment connected on this circuit breaker.  Whenever a  call accounting system  (third-party device) is deployed,  connection is often  no  more  complicated than  using  a straight-through, 9-pin, female  to  male,  serial  cable. (Use Radio Shack model 26117B for good  results.) Connection to the PC/call accounting system is  made via an  available 9-pin serial port connector that is designated as COM1 or COM2  in the PC configuration. Once the cable is linked between  the collection device and the DX-80 CPM-SMDR port, the collection device  must  be  programmed  for compatible  link protocol (baud rate). At default the SMDR  port baud rate is set  at 9600  bps.

Assigning a Password to the Extension

Assigning a Password  to the Extension All extensions of the DX-80 system have an  associated user password.   Passwords  are required to use  Phone  Lock,  Call  Forward  Remote, and Attendant features.   Note:   Extension passwords  can be changed  at  the extension  only by using  the Phone Lock  feature. Passwords can be  from four  to  eight characters  in length.   You  may  want to program the overall system password length before programming individual  extension  passwords.   See  Section 4.4,  Setting User Password  Lengths, Setting Passwords for System Directory  Numbers  101, 102,  and  108  for more details. Changes to  the length of the  user  password affect existing passwords—the system adds or  subtracts one default character  to  the end of  the  password.  That is,  if you extend the length  of  the password, the system increases all passwords by adding a 0 in the  right-most  position.   If you  reduce the  length of the password, the system truncates all passwords  by one  character in  the right-most position.

save current setting

The  system prompts “Save Current Setting?”   Press  Y  to  save  your changes. 9. The  system  then  prompts “File Exists, Override?”   Press  Y  to  continue with the save operation. 10. Press  Esc  to return to the  Uniform Call Distribution: Parameter Processing: Hunt  Group 24 menu.  Press  Esc  three times more to return to  the Database Programming  menu. 11. Next,  program the voice mail  hunt  group.   Highlight  Voice Mail  Table, and  press  Enter.  Choose the tenant  group  you want  to program, and press Enter.   The  system  displays the  Extension Application—Voice Mail  Table: Tenant  x  menu.

KSU1

You can add one AAM to the KSU1.  The  AA  Module  adds  automated attendant  functionality to the DX-80 system with 10 integrated  announcements.   The  AAM does  not  provide voice mail functions. For details on how to program the AAM  and its announcements, refer to the  DX-80 Technical  Manual, Volume  II,  Programming. Install  the AAM onto designated  connectors located on the CPM. To  install the AAM perform the  following steps. 1. Be sure  that the  entire system is turned off. 2. Remove the  KSU  cover (four screws at each corner). 3. Connect  a static discharge  wrist  strap to a  suitable  earth  ground.   Be sure  that the strap  is touching bare skin.

Analog ports

Programming Third  Party VM, Analog Ports You can  connect the DX-80 system  to  a third-party voice mail system using spare analog  ports.  Doing so  occupies these ports and therefore reduces the  number  of system ports that  you can use for the telephones, FAX machines, modems, etc. Comdial recommends  using the  DX-80 DX-SO  voice  mail  system, because  it is a digital  integration and therefore does not occupy valuable analog port space of the DX-80  system.  For further details,  see Section 9.2,  Programming Optional Internal VM,  Digital. Using voice mail greatly enhances  the  use  of the  DX-80 system.  Features  accessible  when voice  mail is installed  vary  depending  upon  the  third-party  product connected.   Features  that the  DX-80 system accommodates include the following. •   Automated Attendant •   Extension unique voice  mailboxes •   Call  Forward to extension voice mailboxes •   Answering Machine Emulation •   UCD Queue  Announcements •   Menu Routing •   Voice Record •   Automatic Voice  Record •   Specific  CO  Line  Greetings on  Automated Attendant The following  conditions apply to analog voice  mail. •   Voice mail  feature  operation is limited  only by the ancillary voice mail  system. •   When voice mail ports are used  heavily (high call  traffic), the  system  updates message indications  notably slower than usual. •   When VM  messages are waiting, the  system flashes the auxiliary lamp green.

COM4

Adding a COM4 You can add one COM4  to KSU1  and  one COM4  to  the KSU2.   These modules  expand  the  DX-80 system  CO  line  interface  capacity to a  maximum of eight  CO line  ports in each KSU  (16 total CO line ports when used in KSU 1 &  2). When  adding  a COM4 to  either KSU,  connect to  the  408M/E  via the COM4  module ribbon  cable.  This ribbon cable has the logical system  address  of SLOT 5  in both cabinet 1 (KSU1-408M) and cabinet  2 (KSU2-408E).   COM4 modules are  installed using  four  1.5 cm brass-color standoffs.   Always install  the COM4  module beneath the  CPM  module (in KSU1) by first  removing the CPM, installing the  COM4,  and then re-installing the CPM.  This is required whenever  you install  the InSkin Voice  Processor.

peripheral processor

The  408M is equipped with a heartbeat LED that  indicates processing  activity  on  the PCB.  (The 408M peripheral processor  is  operating when  the heartbeat LED  is flashing.)  The KSU1 operation LED (located  next  to the power switch) is  tied to the  408M heartbeat LED.   Therefore,  when  the  LED next to the power switch is flashing,  the 408M is active. The  KSU1-408M  has three ribbon cables: •   located at the upper  right and oriented  in a horizontal  position, the J1  cable is used to interface a COM4  if required to expand  the system CO line  capacity. •   located at  the  upper center  and oriented  in  a  vertical position,  the J4  cable  is  used to interface the DX-80 CPM. •   located at the upper  center  and oriented  in a vertical position,  the J5 cable  connects to  the standard APM4 installed  in KSU1. Each CO line circuit  incorporates  over-voltage  protection, ring  detector, loop  detector, loop/pulse-dial relay,  current sink circuit, coupling/isolation transformer (impedance  600:600), hybrid  circuit, CODEC & filter,  polarity guard  circuit  and Radio  Frequency noise filter. The  fourth CO line port is equipped with  CNG Fax  Tone  Detection circuitry.   When  programmed  as  a “FAX” line, this circuit will automatically engage the FAX Tone detector.  If FAX tone is detected, the system routes  the call  to the analog port  designated as the destination for  fax calls.