Minimaster 1 Installation Manual

Sales Brochure - PHME0107

PXML No. 84

DEC 1982

This is to introduce the Minimaster 1 which is one of a family of small switching systems providing up to six extensions with one exchange line. It is ideally suited to the small Business and Residential markets, providing basic PABX type facilities without the need for dedicated terminals, or a switchboard; facilities being accessed via the dial or keypad.

1. The Minimaster 1 is a microprocessor controlled small switching system which consists of a mains powered, wall mounted control unit (similar to the Ambassador ESS 1+3) to which, up to six basic/premium telephones are individually connected by means of a pair of wires.

2. The use of ordinary telephones as extensions allows a wide choice of styles and colours to be used, but due to technical difficulties Statesman and Sceptre 100 cannot be used with this system at present.

3. The system is only available with loop disconnect signalling.

4. Dimensions of the control unit are: 300m x 200mm X 75mm.

5. The colour of the control unit is light grey.

6. An adjacent power point, minimum 3 amp rating must be provided by the customer.

The following facilities are available:-

  1. BOTHWAY, exchange line access

  2. HOLD, any extension may hold an E/L or intercom call while making an enquiry of another extension. In the event of an exchange line call being put into Hold and forgotten, the holding extension will be reminded by a short burst of ringing approximately every 15 seconds.

  3. TRANSFER, extensions can transfer E/L or intercom calls to another extension within the system (including an unattended extension).

  4. CONFERENCE, between the exchange line and two extensions or between three extensions.

  5. INTERCOM, by dialling the appropriate extension number.

  6. DIVERT, extensions may divert internal calls to ring at another extension.

  7. CALL PRIVACY, exchange line and intercom calls are private from other extensions.

  8. CALL BARRING There are 4 system options of call barring. Each option provides two choices of barring. These can apply to all extensions except extension 1 which cannot be barred at all. Once a barring option has been chosen, it can only be changed by a BT engineer.

Barring options are as follows:-
(i) No Barring or full barring

(ii) No Barring or IDD barred

(iii) IDD barred or IDD and STD barred

(iv) IDD barred or full barring

Once a barring option 1-4 has been chosen, one of the two alternatives for each extension is then programmed by the installer. It is important that customers are made aware of the following points:-
(a) IDD and STD call barring applies to dialled calls only, it does not apply to operator controlled calls.

(b) Full barring does not allow 999 calls

(c) STD barring will also prevent the dialling of local calls beginning with 101.

Telephones connected to the Minimaster1 ring sequentially, not together. There is a choice of ringing programmes (5 in all) which will ring 1, 3 or all 6 telephones. The ringing cycle is repeated until the call is answered or the caller clears down.
Programme 1 rings extension 1 only
Programme 2 rings extension 2 only
Programme 3 rings extension (in that order)
Programme 4 rings extension 1.3.5 (in that order)
Programme 5 rings all extensions 1- 6 in sequence

The sequence of ringing is 6 rings at the first extension, 4 rings at the second and third extensions then 2 rings at each subsequent extension. During the ringing cycle the call can be answered at any extension that is not ringing by lifting the handset and dialling 8. A full ringing sequence, i.e. all telephones rung, takes approximately 1 minute.

The customer selects the most suitable ringing programme which is programmed on installation. Because of the exchange line ringing cycle and the mains failure facilities, the customer should give careful consideration to the extension numbering scheme.

Additional sockets may be provided on extensions, within the normal limits.

Minimaster 1 will cater for external extensions working within the prescribed transmission limits.

Under mains failure conditions extension 1 becomes a direct exchange line, all other facilities are lost.

Operating instructions will be included with each control unit.

1. As a first step in the market with this type of product, contracts have been placed with two contractors for different versions of Minimaster. The first of these is Minimaster 1 which is currently undergoing trial in the Tunbridge Wells Telephone Area of BTSE. Marketing will follow in the remainder of BTSE and then be extended to BTL and BTM by the end of 1982.

The second system, to be marketed as Minimaster 2 will be supplied by another manufacturer and be available to the remaining 7 regions from the end of 1982 early 1983. The Minimaster 2 has a capacity of 1 exchange line and 5 extensions, provides similar facilities to Minimaster 1 and will be the subject of a separate BTHQ Circular.

2. Minimaster systems will not, initially be nationally promoted. However, Regions/Areas may originate their own local campaigns in order to create awareness.

Minimaster 1 may be used in all situations EXCEPT:

(a) Shared Service

(b) MF PBX's and exchanges

(c) As plan extensions

(d) DC CODE C systems

(e) Statesman and Sceptre telephones are not suitable

The following telephones are suitable as extensions to Minimaster 1 Basic dial/press button, Ambassador, Astrofon, Candlestick, Contempra, Viscount.

Battery powered telephones i.e. Xpress callmakers and early versions of press button telephones e.g. Telephone No. 764, must be provided with Power Unit No. 53B when used on extensions of Minimaster 1.

NOTE: When Minimaster 1 is used on PBX extension, the telephones associated with Minimaster must be fitted with a recall button.

TWO NEW wall-mounted small switching systems are being introduced this year. The systems - the Minimaster 1 (1 + 6) and Minimaster 2 (1 + 5) - are aimed at small business customers but the choice of extension telephones will make the systems attractive to residential customers as well. As a first step into these markets, contracts have been placed with two manufacturers for the different versions of Minimaster. The systems are similar in design, comprising a mains-powered central control unit to which extensions are individually connected. Minimaster 1 is currently being trailed in Tunbridge Wells telephone area and Minimaster 2 is shortly to undergo trials in Southend area.

Taken from BT Management News - April 1983

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