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Old 15th Mar 2011, 10:19 pm   #1
Dave Moll
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Default BT Herald PABX

First, may I give a big thank you to llama, who supplied me with three Amphenol connectors (see this thread) and AndiiT, who has pointed me in the direction of wiring conventions and manuals for a system that uses similar Amphenol connectors.

The wiring on this system is not what I would call intuitive, but I do feel that I have now made a degree of progress in identification.

A bit of background: there are three cables (apart from the mains!) issuing from the control unit, each of which ends in a fifty-way Amphenol connector - marked "A", "B" and "Z" respectively. Spread across the A and Z cables, I have identified a total of sixteen groups (some four-wire and some two-wire) that operate as extensions. On all but two, I have identified the extension numbers by which they are known. I've not identified anything on the B cable.

Now we come to the crunch. There are still many positions whose function I've not yet confirmed. As extensions start at the "upper" end of the Z cable and continue on the lower part of the A cable, I strongly suspect that the first few pairs on the Z cable are the (undefined number of) exchange lines, but I'm wary of connecting a (simulated) exchange line to something that would take exception to being zapped with 50V DC. I suppose what I'm really seeking is reassurance that I'm not taking too much of a risk by connecting (say) the first pair of the Z cable as an exchange line to see whether I can communicate.

It would be a bonus if I were able to identify some of the other facilities (such as music on hold etc), and even how to programme the system!
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Old 16th Mar 2011, 10:14 pm   #2
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Default Re: BT Herald PABX

Hi again,
From the exchange line point of view a 9 Volt battery across the exchange pair(s) should cause a click in the earpiece of any associated extension switched to the appropriate line, this may pose a problem if you don't have any system phones or know what the "exchange line" digit is required from a POTS telephone - with many systems of this type the aforementioned digit is 9 but in some cases may be 0.

In order to meet BT approval, these systems had to have "mains fail working" allowing selected extensions to be connected directly to exchange lines during mains failure, usually the lowest extension number (i.e. 1, 21, 101) would be connected straight through to exchange line 1 when no power is applied to the system.
If you are lucky this will be done by a relay in the CCU and once you have identified the lowest numbered extension port, if you are able to, you may be able to "back trace" from there, using a multimeter set to low ohms range, to exchange line 1 - this could give you a starting point for the exchange line pairs at least.

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Old 16th Mar 2011, 11:40 pm   #3
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Default Re: BT Herald PABX

Since my initial post, continuing investigations have identified the following connections:
Code:
Z1	exchange 1?			A1	extn 134
Z2	exchange 2?			A2	(x134 data?)
Z3	exchange 3?			A3	extn 136
Z4	more exch lines?		A4	(x134 data?)
Z5					A5	extn 138
Z6					A6	(x138 data?)
Z7					A7	extn 141
Z8					A8	extn 144
Z9	extn 0 (operator)		A9	?	
Z10	(x0 data)			A10	?
Z11	extn 124			A11	?
Z12	(x124 data?)			A12	?
Z13	extn 133 			A13	?
Z14	(x133 data?) 			A14	?
Z15	extn 139			A15	?
Z16	(x139 data?) 			A16	?
Z17	extn 125			A17	?
Z18	extn 126			A18	?
Z19	extn 127			A19	?
Z20	extn 128			A20	?
Z21	extn 129			A21	?
Z22	(x129 data?) 			A22	?
Z23	extn 131			A23	?
Z24	extn 132			A24	?
Z25	(not used) 			A25	?
The reason I've put question marks against the data pairs is that I was rather surprised to find that a system 'phone seems to work equally well without the data pair connected, and some extensions clearly ARE single pairs. I'm sure that a little further investigation will identify function(s) that don't work without the data pair. I was particularly pleased to identify the connections for the operator's keystation (which I do have) and have established that its functions work correctly.

A word about extension numbers: Initially, I laboriously worked my way through combinations of keypresses identifying sequences (including a single zero) that resulted in a ringing tone (not quite as lengthy as might initially seem as no combination is more than three digits*, and some first digits fail (giving NU tone) without further keypresses). On each pair identified as the voice pair of an extension (identified by connecting a 'phone to each pair in turn) one of the valid numbers gives a busy tone rather than ringing, thus identifying the number of the extension being used. The exception was the extension on pair Z9, which rang for EVERY valid extension number, but when I realised that this was the only extension that gave NU tone when pressing zero it dawned that I was connected as the operator!

*obviously, the exception is sequences starting with nine - but I already knew that this is for making external calls.

Given what I have identified so far, I am now reasonably confident that at least the first three pairs on cable Z are for exchange lines as there are three buttons for external lines on the operator's keystation. There are possibly also pairs for power-fail bells? I think my first line of investigation will be Andi's suggested battery test as the least likely to cause damage. I shall then give these lines a work out using the test equipment at my disposal. I may even eventually take the bull by the horns and try plugging a line into a REAL telephone socket.
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Old 17th Mar 2011, 1:52 pm   #4
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Default Re: BT Herald PABX

Quote:
Originally Posted by AndiiT View Post
From the exchange line point of view a 9 Volt battery across the exchange pair(s) should cause a click in the earpiece of any associated extension switched to the appropriate line
I tried each of the first eight Z pairs with a PP3 and unfortunately was unable to obtain a crackle.

Using my Marquis II, I confirmed that the technique works on each of its four exchange lines.

I'll try again with the unidentified pairs at the other end. If I include the B cable, there are a fair few to choose from.
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Old 17th Mar 2011, 4:06 pm   #5
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Default Re: BT Herald PABX

I've now tried all the remaining unidentified pairs (on cables A and B), but the exchange lines continue to elude me. I also tried connecting my linesman to A1 just in case it only responds to a real line voltage, but still nothing.

I then turned to identifying data pairs for system 'phones. First, I have to confess puzzlement at yesterday's results. I can only assume that I had the 'phone plugged into a different socket from the one on which the data pair was disconnected. Today, the only thing I get on a system 'phone without its data pair connected is a dial tone (and the ability to answer incoming calls) - even the keypad doesn't work. This means that I have now identified that x124 (Z11/Z12), x133 (Z13/Z14) and x139 (Z15/Z16) are the only system 'phone (two-pair) connections. The rest are single-pair - including a few I somehow missed before (A2=x135, A4=x137 and A6=x140). Incidentally, now that I have the "operator" connected, identifying extension numbers is greatly simplified as it displays the number of an extension ringing in!

And another thing - I had been warned about ensuring correct polarity on data pairs, but I accidentally discovered that connecting the data lines of a system 'phone to a voice pair cause it to light up like a Christmas tree (with all its indicator LEDs alight)! Fortunately, no harm was done.
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Old 17th Mar 2011, 9:55 pm   #6
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Default Re: BT Herald PABX

Hi,
Good to know that you seem to be making massive progress with this system.

You have confirmed, as I believed, that the system phones will only operate correctly with the data pairs connected.

Regarding exchange lines it may be that the system has only been programmed for three exchange lines, extra lines requiring provision in the software programming (which would be in the manual which I don't think that you have ) additionally the operator terminal may only have three exchange line "appearances" but with most systems of this type exclusive exchange line access can usually be obtained by dialling a two digit number; The BT Revelation system, for example, will give the first free line if 9 is dialled or allow exclusive access to line 1 by dialling 51, Line 2 dial 52 and so on. I think that the Minimaster 3 uses 31 and 32 for the same function.

There won't be any mains fail bell connections, during mains fail calls had to be connected to selected telephones, I think that the "standard" requirement was 20% of the total number of lines provided had to be made available for connection for outgoing calls. There may be a connection for a central bell though, which would be one that rang to incoming calls on any exchange line.

Some common numbers used on most PBX's and their functions are listed below (you will already know some of these)

First available exchange line access - 9
Dial Answer Night Service - 8
Inter PBX access - 7
Direct exchange line access 5X or 3X
Extension Pick Up 4X (Ext. No.)
Answer non ringing extension 6X
Operator (this may be also the lowest extension number in the range for example 21 or 101) - 0
Number in the 1X(X), 2X(X) and 3X(X) range would most likely be reserved for extension use depending on the capacity of the system.
Some of the numbers used for "facilities" might double up on function, 43 may be used for extension pick - up whilst 48 might be for call diversion.

I think that I may have some information abut a Herald PBX in a THG magazine, I'm not sure if it will be of any use but I'll dig it out just in case.

Please continue to keep us informed of your progress.

Regards
Andrew
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Old 19th Mar 2011, 3:12 pm   #7
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Default Re: BT Herald PABX

Some further information on the "software" side of things...

It seems that there are only TWO external exchanges activated (I'm sure there were three, but the third one seems to have stopped working and the button on the operator keystation no longer works). Dialling "9" on one extension gets the first exchange line. Doing the same on another gets the second one. The third extension gets a busy tone.

As the third line can be selected by dialling "71", I assume this to tie in with Andrew's note above about inter-PBX.

In addition to the extension numbers already mentioned in the thread, two further numbers (233 and 238) also dial out, but have no circuits assigned to them. Also the operator display does not show their number when dialling them like it does with the "real" extensions.

There are twelve numbers starting with "6" that are presumably for special functions, some of which can only be used by the operator. As one (641) gives a message "your key is programmed to", I assume that some of these are associated with programming the control unit*. Others that I have identified are:
631: set night service 1
632: cancel night service
638: set night service 2
675: identify extension number

Interestingly, when 675 is entered from the operator keystation, the answer is "extension number 123" (one below the lowest extension number assigned).

*I may, of course, have accidentally reprogrammed the third outgoing line!

As stated above, "71" gives access to line three, "9" gives next available exchange line and "0" rings the operator. All other numeric key combinations result in an NU tone. I didn't try "*" and "#" on the assumption that they were used for programming purposes.
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Last edited by Dave Moll; 19th Mar 2011 at 3:17 pm. Reason: note about "*"/"#" added
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Old 19th Mar 2011, 3:21 pm   #8
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Default Re: BT Herald PABX

Nope. Having just tried them, "*" and "#" both give NU tone as well.
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Old 19th Mar 2011, 9:06 pm   #9
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Default Re: BT Herald PABX

Quote:
Originally Posted by Dave Moll View Post
As the third line can be selected by dialling "71", I assume this to tie in with Andrew's note above about inter-PBX.
It's more likely that 71 has been programmed as part of a "group" which allows line 3 to be accessed - for instance on my Revelation I can also access the first available exchange line by dialling 71 and think that 71 to 73 can be programmed for exchange line group access.

Inter - PBX working is where one (or more) exchange line(s) of a PBX is "tied - in" to another PBX in another building or some distance away, for instance you may have two separately sited buildings, such as a Hospital or Police station, which are large enough to require a PBX in their own right but also require extension users in one building to be able to contact extension users in the other building, this would be achieved by prefixing the required extension number with the appropriate the inter PBX digits; This avoids the call being routed out to the PSTN and back and, essentially, treats the call between buildings as an "internal" call. (If the buildings are some distance apart the call may go through a number of exchanges but on a Private Wire)


Quote:
Originally Posted by Dave Moll View Post
Interestingly, when 675 is entered from the operator keystation, the answer is "extension number 123" (one below the lowest extension number assigned).
Have you attempted to dial 123 from another extension to see if the operator telephone rings?

Regards
Andrew
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Old 19th Mar 2011, 9:25 pm   #10
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Default Re: BT Herald PABX

Yes, I have already tried dialling 123 - it gives NU tone.

As far as I am aware, my previous post gives a comprehensive list of the only number sequences that give anything other than NU.
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Old 19th Mar 2011, 10:58 pm   #11
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Default Re: BT Herald PABX

Dave

Max at this location may be able to help you.

http://www.s1darvel.com/groups/darvel-telephone-museum/
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Old 19th Mar 2011, 11:50 pm   #12
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Default Re: BT Herald PABX

Quote:
Originally Posted by Dave Moll View Post
Yes, I have already tried dialling 123 - it gives NU tone.
I am guessing that as far as the system is concerned the operators terminal is actually designated extension 123 but is programmed, perhaps permanently in this case, to only apply ringing (and give ringing tone) when 0 is dialled in order to save any confusion in the event of a mis-dial from any of the other extensions.

Regards
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Old 20th Mar 2011, 5:34 pm   #13
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Default Re: BT Herald PABX

Quote:
Originally Posted by Racal Zonal View Post
Max at this location may be able to help you.

http://www.s1darvel.com/groups/darvel-telephone-museum/
Thank you. Email sent to him.
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Old 27th Mar 2011, 7:47 pm   #14
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Default Re: BT Herald PABX

Meanwhile, I have acquired a manual entitled "British Telecom Documentation System (Pentara+Plus)". Although it hasn't been as enlightening as I had hoped, I have picked up one or two tidbits of information and confirmed conclusions arrived at experimentally.

Having acquired the manual, I discovered that it is, in fact, the instructions for using a suite of DOS-based programs to construct the configuration database for a Herald system and to transfer it to/from the control unit. Sadly, the software itself was not included. I suppose it's way too much to hope that the programs exist as a download somewhere. The Pentara Documentation System package is listed as containing the following programs:
Code:
V10ONE.EXE	ONE.BAT		PDS.BAT
V10TWO.EXE	TWO.BAT		ASK.COM
V10THREE.EXE	THREE.BAT	SELECT.COM
V10FOUR.EXE	FOUR.BAT	INSTPDS.BAT
V10FIVE.EXE	FIVE.BAT	INSTPDS2.BAT
V10SIX.EXE	SIX.BAT		I.TXT
V10SEVEN.EXE	SEVEN.BAT	SWAPCOM.COM
TD1102.PDS			README.TXT
TN1102.PDS
TP1102.PDS
The manual has confirmed that the primary digit numbering system (at default) is:
Code:
Digit	Access				No.
0	extension			0
1	extension			123-199
2	extension			200-237
3	no function
4	abbreviated dialling		400-499
5	no function
6	dial up facility codes		600-675
7	private cct group access	71-79
8	dial up facility codes		8
9	exchange group access		9
#	no function
There is also reference to setting up dummy extension numbers to signal a group of extensions, which would explain the oddball extension number of 233. In fact, although I haven't fully identified the list to which this relates, I now know that extension 137 is one of them, so it's a matter of prodding around to see which circuits are signalled when this number is ringing out. Given that the stated range ends at 237, I am a bit puzzled by the other oddball, which is 238.

Among the other amazing facts are the maximum capacities available (subject to the appropriate hardware being installed):

112 exchange lines
112 4-wire extensions (i.e. voice pair + data pair)
116 2-wire extensions (i.e. voice pair only)

Unfortunately, I am still no further in identifying further physical circuits (such as exchange lines), nor detail of the remaining facility codes between 600 and 675.

As I say, an interesting acquisition, even if not quite what I was after.
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Old 27th Mar 2011, 11:52 pm   #15
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Default Re: BT Herald PABX

Wasn't the Herald programmed by burning custom eproms?
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Old 28th Mar 2011, 12:33 pm   #16
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Quote:
Originally Posted by Dave Moll View Post
the oddball extension number of 233... although I haven't fully identified the list to which this relates...
I have now (131,136,137,140,144)

238 remains a mystery. It rings out but doesn't signal any circuits. I have also noticed another oddity with it: Whereas dialling an extension from the operator keystation displays "extension [nnn] ringing" and 233 displays nothing, 238 displays "extension [blank] ringing" (where the [blank] represents the three positions that would normally contain the digits).

As for programming, the manual implies that the later (Pentara) versions use EEPROMs that can be programmed via a serial or parallel connection to a PC. It may that the earlier versions required EPROMs to be burned externally.

According to Bob's Telephone File, what I have appears to be a Pentara Plus.
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Old 5th Apr 2011, 8:17 pm   #17
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Default Re: BT Herald PABX

Quote:
Originally Posted by Dave Moll View Post
Unfortunately, I am still no further in identifying further physical circuits (such as exchange lines), nor detail of the remaining facility codes between 600 and 675.
A little further progress with the latter:
622 followed by up to three digits diverts the extension's incoming calls to the extension number identified by those digits
623 cancels the above
641 identifies (vocally) any keys pressed following it

Although I have not identified any other functions, I have established that 626 accepts up to three digits in the same manner as 622 (so is presumably also something to do with call diversion), but I have not been able to identify the effect of following it with a valid extension number. Incidentally it does not differentiate between valid and invalid numbers (unlike 622 which gives NU if the extension number is unacceptable). It seems reasonable to presume that 629 cancels whatever effect 626 is supposed to have.

Based on information given to me, I had wondered whether 626 was for pick-up of a call to another extension, but it doesn't do so, and there doesn't appear to be a way to do this.

657 is only acceptable from the operator and awaits further digits to follow it. I am reluctant to experiment further with this one as I suspect it to be related to self-configuration of the control unit - being the one 6nn code which is accepted from the operator but considered invalid from a user extension.

In summary the codes identified so far are:
622nnn: divert incoming calls to extension nnn
623: cancel diversion of incoming calls
631: night service 1 (operator only)
632: cancel night service (operator only)
638: night service 2 (operator only)
641: identify following keypress(es)
675: identify extension number (operator = 123)

unidentified codes: 604, 617, 626nnn, 629, 657(operator only), 666
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Old 5th Apr 2011, 9:07 pm   #18
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Hi,
Regarding the call diversion options, if 622 is divert to nnn and 623 is cancel divert, it is likely that 624 (nnn) could be "Divert on busy" and 625 cancels this, 626 (nnn) may be divert on no answer with 627 being the cancel code for this.

These are all (un)educated guesses based on the way other PBXs facility codes are designated.

Regards
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Old 5th Apr 2011, 10:38 pm   #19
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Default Re: BT Herald PABX

Sorry, I've already eliminated those possibilities. First, as I have said, the above-mentioned codes are the only ones that are accepted. 624, 625 and 627 simply give NU.

What I omitted to mention was that I had also eliminated 626 as being divert on no answer (and as divert on busy) by dint of the extension where I had entered the code continuing to ring for a couple of minutes (longer than any reasonable caller would wait before giving up), and by simply getting busy tone when ringing it while off-hook.

edit: the list of unidentified codes should also include 614, 615 and 620. Just to clarify, entering the code simply returns to dial tone without any detectable effect. 626 and 657 are the only unidentified ones that allow further digits to be entered.
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Old 7th Apr 2011, 9:57 pm   #20
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Default Re: BT Herald PABX

Hello,

I have found the attached site that gives the use of 657,650 and 656

http://www.britishtelephones.com/tim...htm#pentara100


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