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Old 12th Feb 2017, 9:50 am   #1
Dave Moll
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Default BT Senator PABX - unable to make internal calls

As per the title, I am unable to dial internal extensions on my Senator system. According to the user manual (thanks to G8KBG Tony for the link):
Lift your handset...

Listen for the internal dial tone.

If you hear the dial tone, key the number of the extension you want by pressing the appropriate button on the keypad. (For extension 10, press [0].)


I do hear the internal dial tone when I lift the handset, but when I press the appropriate number key, it drops me straight back to dial tone once the train of loop disconnects has completed.

I am able to make and receive external calls without problem, so clearly the keypad buttons are operating correctly.

The problem occurs with extensions on either of the two functional extension cards* fitted, so any suggestions for what to check out would be appreciated.

*It came with a third card, but this appears to have a fault, so is currently removed from the system. Its fault is outside the scope of this query.
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Old 12th Feb 2017, 1:19 pm   #2
OscarFoxtrot
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Default Re: BT Senator PABX - unable to make internal calls

I think the Senator uses either pulse or tone depending on its intercom card. It may not be possible to mix the two.

DPA1210A LD Intercom Card to make system pulse dial
DPA1217A MF Intercom Card to make system tone dial

You may have a switch on the base of the phone to change from pulse to tone dial to make the phone compatible with the intercom card installed.

http://www.samhallas.co.uk/repositor...or1_system.pdf

In external calls the phone is connected directly to the exchange line.
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Old 12th Feb 2017, 4:00 pm   #3
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Default Re: BT Senator PABX - unable to make internal calls

Yes, I'm aware of the two Intercom Cards. Mine is the 1217A MF version. I didn't realise, however, that this meant that Ambassador/Senator stations also come in LD and MF versions that have to match the intercom card fitted, rather than using the data pair to communicate the keys pressed as they presumably do for the function keys. On this basis I was a little surprised to hear a series of LD pulses when I pressed a number key.

By the way, there is no sign of an MF/LD switch on any of the units.

Thanks, by the way, for the link to the "Guide Notes". I had found the summary on Bob Freshwater's site, and an earlier thread seeking manuals had resulted in a link to the user manual, but this looks much more detailed and I shall read through it before proceeding further, but it looks as though it may not be possible to use my existing Ambassador stations with the Senator CCU.
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Old 12th Feb 2017, 4:06 pm   #4
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Default Re: BT Senator PABX - unable to make internal calls

Your post doesn't make it clear which intercom card you have; but the fact that it drops straight back to dial tone is indicative that either your intercom card is u/s, or of the wrong type.

You can't mix MF and loop-dis dialling on a Senator (or it's half-brother, the Ambassador, either)

The only switches of this era on which you can freely mix MF and loop-dis dialling, are the Mitel ones; Viceroy/Kinsman/TSX50/Regent.
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Old 12th Feb 2017, 4:31 pm   #5
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Default Re: BT Senator PABX - unable to make internal calls

Quote:
Originally Posted by Dave Moll View Post
Yes, I'm aware of the two Intercom Cards. Mine is the 1217A MF version.
As a test could you try sending MF down the Senator extension's transmitter from a handheld tone generator (or another phone connected to another line) and see if that will activate the Intercom Card?
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Old 12th Feb 2017, 4:48 pm   #6
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Default Re: BT Senator PABX - unable to make internal calls

Prior to reading this update, I had done just as OF suggests and indeed it does have the desired effect. Conclusion is that my Ambassador telephones are not compatible with the Senator CCU. To make internal calls with the Senator without using an external dialler, it looks as though I shall have to try finding some MF Senator 'phones (or a 1210A LD intercom card)!
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Old 12th Feb 2017, 8:31 pm   #7
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Default Re: BT Senator PABX - unable to make internal calls

Quote:
Originally Posted by Thyristor View Post
You can't mix MF and loop-dis dialling on a Senator (or it's half-brother, the Ambassador, either)
I now appreciate this with the Senator, where the intercom card handling internal communication accepts either MF tones (1217A) or LD pulses (1210A) to connect internal calls, but isn't the Ambassador indifferent to the signalling method if it is only used on external calls where the station is connected direct to the exchange, internal calls being connected by pressing the appropriate extension button?
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Old 13th Feb 2017, 7:08 pm   #8
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Default Re: BT Senator PABX - unable to make internal calls

From memory, no; but it was a very long time ago.

On an Ambassador, I think the extension button triggers either the appropriate MF4, or loop dis, tones/pulses, as appropriate, to 'call' an extn.
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Old 13th Feb 2017, 8:56 pm   #9
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Default Re: BT Senator PABX - unable to make internal calls

I don't see how that can be, given that the same button on the telephone calls an extension on the Ambassador and connects to an exchange line on the Senator. Also, interconnection on the Ambassador is immediate, whereas I would expect a pause while the LDs are transmitted. Certainly, no LD clicks are audible when pressing an extension button.
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Old 13th Feb 2017, 9:49 pm   #10
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Default Re: BT Senator PABX - unable to make internal calls

Quote:
Originally Posted by Thyristor View Post
....On an Ambassador, I think the extension button triggers either the appropriate MF4, or loop dis, tones/pulses, as appropriate, to 'call' an extn....
As far as I am aware the Ambassador and Senator use totally different protocols/signalling methods when calling an extension.

The Ambassador uses a data bus that is monitored by the CCU till an exchange line or extension button is depressed and then instructs the processor accordingly; for exchange line access on the Senator I would guess that a similar process is used as that on the Ambassador, whilst extension access is done in the "traditional" way using a digit register.

Both the Senator and Ambassador are nice reliable systems their downfall being the fact that they require dedicated system phones unless you are lucky enough to have some "two-wire" analogue terminal adapters which are rarer than hens teeth.

Regards

Andrew
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Old 14th Feb 2017, 9:24 am   #11
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Default Re: BT Senator PABX - unable to make internal calls

That would confirm the conclusion I have reached by empirical methods.

What threw me in the first place was being more familiar with the way Herald/Pentara systems handle their four-wire system 'phones. Of course, unlike the Ambassador/Senator ones, these can't be used on an ordinary two-wire connection, given that they don't generate the LD pulses/MF tones themselves.

Thanks, also, for confirming the impression I had reached concerning the rarity of the analogue terminal adaptors for Ambassador/Senator systems.
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Old 14th Feb 2017, 10:03 pm   #12
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Default Re: BT Senator PABX - unable to make internal calls

The 'new' AESS Terminals 8560 & 8561 support LD & MF signalling with switches on the base.
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Old 15th Feb 2017, 8:43 am   #13
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Default Re: BT Senator PABX - unable to make internal calls

How do they compare with hens' teeth for availability?
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Old 15th Feb 2017, 6:17 pm   #14
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Default Re: BT Senator PABX - unable to make internal calls

Ebay 272555121126

£80 for a complete Ambassador system with 4 new-stylee phones. If you don't want the control unit you could probably sell that separately. Or have some 4-pole changeover switches and have two systems to play with, erm preserve and demonstrate.
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Old 16th Feb 2017, 9:24 pm   #15
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Default Re: BT Senator PABX - unable to make internal calls

I think I only ever saw one or two of the 4w - 2w converters; used for external-extensions, ISTR.
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