Programming the Mitel SX-20 PABX

People keep asking me, "How do I program my SX-20? I don't have a manual!"

As far as I know, the manuals are no longer available, but I've put together this website to give you a quick summary of the important commands on the SX-20.

I have one of these PABX's running at my house, and have had requests for information, so I've decided to create a webpage.


WE DO NOT PROVIDE SUPPORT FOR THE SX-20, SO PLEASE DON'T WASTE BOTH OUR TIME ASKING. IF YOU HAVE QUESTIONS THAT ARE NOT COVERED BY THESE WEBPAGES, PLEASE CONTACT MITEL OR YOUR DISTRIBUTOR.
SX-20 with cover on
SX-20 with cover on
SX-20 with cover off
SX-20 with cover off

Disclaimer

The information on this web page is intended to be helpful, but we cannot be held liable for any use of this information. Use at your own risk.


WE DO NOT PROVIDE SUPPORT FOR THE SX-20, SO PLEASE DON'T WASTE BOTH OUR TIME ASKING. IF YOU HAVE QUESTIONS THAT ARE NOT COVERED BY THESE WEBPAGES, PLEASE CONTACT MITEL OR YOUR DISTRIBUTOR.

On this webpage...

This webpage contains:

You might also be interested in the 50 pole, double throw "cutover" switch I built for cutting over the lines on the PABX in case of a power failure.


Overview

The Mitel SX-20 is a Private Automated Branch eXchange (PABX) suitable for a house through to a small business. They've also been found in hotel/motels.

Features

Generally, the SX-20 has the following features:

Console

SX-20 console
SX-20 console

The console is your main status and display station for the SX-20 PABX. It's also one of three places where you can perform programming (the other two are the RMATS port (if enabled and present) or the first line (if enabled)).

Remote Console

SX-20 remote console
SX-20 remote console

Programming

This programming section applies to GENERIC 503! See below (under Entering the programming menu) on how to determine which generic ("software version") you have.

Programming of the SX-20 is accomplished from one of three places:


WE DO NOT PROVIDE SUPPORT FOR THE SX-20, SO PLEASE DON'T WASTE BOTH OUR TIME ASKING. IF YOU HAVE QUESTIONS THAT ARE NOT COVERED BY THESE WEBPAGES, PLEASE CONTACT MITEL OR YOUR DISTRIBUTOR.

I tend to program mine from a touch tone phone connected to the first line. In order to program it this way, you will need either a remote console (which is very convenient), or you will need to see the LEDs on the SX-20 box itself. Alternatively, you can either use the RMATS (if you have the RMATS option installed) or the console.

The first thing you need to do is get organized. Do a physical inventory of the trunks and lines that you will be connecting so that you know which ones are which.

Then consult the table below and determine which registers need to be programmed. This is not presented as a tutorial at this time.

Entering the programming menu

First you need to get at the programming menu. We'll use the console as the primary programming interface.

Dial 70.

The console call status should now display ?601, with the "601" part flashing. This indicates that you are in programming mode.

If, instead of a flashing 601 you get a 61, then you have a different version (I've heard "Generic 400" and "Generic 500" but I'm not 100% certain of that) of the software than I have documentation for, and therefore I can't help you :-(

Dial 999 and then *. You should get something that has "503" in it; on mine I get "1 503-04" which shows I'm running generic 503, version "04".)

Hang up. If you did not get a "503", then you can forget about the rest of these webpages, because that's the only version that I have documentation for :-)

When you entered the programming menu, the "601" that was initially displayed is the number of a register. All programming for the SX-20 is done by setting various registers to specific values. The 601 register is the "Systems Options Programming" register. The other registers are as follows (click on the number in the "Register" column for the programming page):

Register Name Purpose
601 Systems Options Programming Defines the options that may be enabled on a system-wide basis.
602 Feature Access Codes Specifies the access codes to be assigned to each feature if the default data is not to be used.
611 - 619 Class Of Service (COS) Programming Each system can accommodate up to nine different COS's. Each COS details which features may be accessed by stations assigned the COS
620 Station Programming Each station in the system may be programmed with a specific COS, Toll Restriction, Pickup Group, and Station Number
621 Station Numbering (Block Programming)This allows rapid/bulk assignment of sequential station numbers to sequential station equipment numbers.
622 COS, Toll Restriction, and Pickup Group (Block Programming)Allows the same COS, Toll Restriction, and Pickup Group access to be assigned to a block of station equipment numbers.
631 - 636 Station Hunting Programming Up to six hunt groups may be defined per system, with each hunt group having up to eight station numbers listed. Hunt groups can be linked to form longer chains.
641 Station Ring Group Programming Up to nine stations can be rung simultaneously by dialling the Ring Group Access Code.
701 - 740 SUPERSET Set Programming Assigns values for up to 16 SUPERSET 3 or 4 sets.
801 - 812 Trunk Programming Programs types, characteristics, and day and night answer modes of trunks.
821 - 826 Trunk Group Programming Up to six trunk groups can be programmed. This command defines their parameters.
910, 911, 920, and 921Basic Toll Control Plan and Digit String ProgrammingA toll control plan defines the sequence and number of digits dialed by a station to access a trunk.
931, 932 Toll Table Item Programming Used to assign individual 3-digit toll restrictions to stations.
941, 942 Toll Table Block Programming Used to assign blocks of 3-digit Toll Restrictions to stations.
970 Busy Lamp Field Programming (Remote and Console Displays)Allows each station to be assigned to a specific busy lamp on the remote and console displays. Assignment is based on multiples of 10, and goes by tens.
972 Function Key Programming A number of the console keys can be programming to have a particular function assigned to a specific key.
975 User-Defined Programming Allows the system programmer to speicfy which system commands may be modified by user programming.
976 System Security Code Programming Defines the 4-digit system security code for system programming access.
977 User Security Code Programming Defines the 4-digit security code for user programming as defined by 975, above.
978 DISA Security Code Programming Defines the 3-digit security code for Direct Inward System Access (DISA).

Error Diagnostics

Click ERROR CODES to display the error codes and their meanings, or ALARM CODES to display the alarm codes.

If you get an error 64, "Corrupted NVRAM", here's the procedure to wipe the NVRAM:

  1. Open cover
  2. Set CPU switches 1 - 8 to required positions (see below)
  3. Set battery switch on PROM board to ON (PROM board is fitted to CPU card)
  4. Turn power on
  5. Set CPU switch 8 on CPU card to closed
  6. press RESET button (below DIP switches on CPU card)
  7. Console display shows 88888888
  8. Console display shows ????????
  9. Within 6 seconds set CPU switch 8 to open
  10. Console display shows --------
  11. Set CPU switch 8 to closed
  12. Console display shows 00-00
  13. Default Data has been loaded

CPU II Card Configuration Switch Functions

The CPU Card switch configuration is as follows:

SwitchFunction
1CLOSED - Cabinet display orientation, desk-mount
OPEN - Cabinet display orientation, wall-mount
2CLOSED - Automatic Diagnostics Enabled
OPEN - Automatic Diagnostics Inhibit
3, 4, 5Reserved, set to CLOSED
6CLOSED - Equipment No. 01 - Station
OPEN - Equipment No. 01 - Test Line
7CLOSED - Three digit numbering plan
OPEN - Two digit numbering plan
8CLOSED - Review Mode
OPEN - Program Mode

Installation

In this section, we'll take a look at the physical connections required to get your PABX running.

There are a number of connectors that you will need to be familiar with:


Console Operations


WE DO NOT PROVIDE SUPPORT FOR THE SX-20, SO PLEASE DON'T WASTE BOTH OUR TIME ASKING. IF YOU HAVE QUESTIONS THAT ARE NOT COVERED BY THESE WEBPAGES, PLEASE CONTACT MITEL OR YOUR DISTRIBUTOR.

Here are the attendant and maintenance function codes:

Function Code
Night Service - ON *11
Night Service - OFF *12
Identifying and Clearing Audible Alarms *13
Set 12-Hour Clock (entered in 24-hour mode) *14 + 2-digit hours, 2-digit minutes
Set 24-Hour Clock *15 + 2-digit hours, + 2 digit minutes
Lamp Test*16
Lamp Test (on Remote Display Only)*16
Background Music - On*17
Background Music - Off*18
Access Trunk by Equipment Number*19 + Trunk Equipment Number
Trunk Emergency Release*20 + Trunk Equipment Number
Flexible Night Service*21 + Truck Equipment Number + New Night Answer Point Station No.
Message Registration / Restrictive Station Control*22 + Station Number
Call Block - On*23
Call Block - Off*24
Access Speech Path by Equipment Number*27 + Speech Path Number
Display All Message Waiting*28
Cancel All Message Waiting*29
Alarm Clear / Cancel Alarm Indications*31
Cancel All Alarms, Alarm Indicators and Busy-outs*32
Busy Out Trunk*41 + Trunk Equipment Number
Busy Out DTMF Generator*42
Busy Out DTMF Receiver*42 + DTMF Receiver Number
Busy Out Dial Tone Detector*44 + Dial Tone Detector Number
Busy Out Speech Path*45 + Speech Path Number
Unbusy Trunk*51 + Trunk Equipment Number
Unbusy DTMF Generator*52
Unbusy DTMF Receiver*53 + DTMF Receiver Number
Unbusy Dial Tone Detector*54 + Dial Tone Detector Number
Unbusy Speech Path*55 + Speech Path Number
To view Speed Dial Numbers programmed at the Prime Station / Console*60 + two digits in the range 10 -> 69
To program the Speed Dial Numbers for the Prime Station Console*65 + two digits in the range 10 -> 69 (when programming the number, you can use the following special sequences: "*1" = 5 second delay, "*2" = wait for dialtone, "*3N" = pause, allow N digits to be dialled manually, "#" = change from pulse to DTMF)
To program Automatic Wake-up at a station*71 + Station Number
To View Automatic Wake-Up at a station*72 + Station Number
Message Registration Audit*73
Printer - Suspend*75 + *
Printer - Purge and Suspend*75 + 0
Printer - Resume*75 + #
Set date at the console*80 + DD-MM-YY
Data Dump*97 + Security Code
Data Load*98 + Security Code
System Status - Trunks#990*
System Status - Stations#991*
System Status - System#992*
Software Identity Display#999*

Common Problems

The following is a list of common problems:

I dial extension XXX from the console, but extension YYY rings instead.
Extension XXX most likely has call-forwarding to extension YYY on it. Go to extension XXX and dial "444" (clear all features) (Note that "444" is the default feature access number for that feature, see register 602, "Feature Access Codes" for details.)