APPROVAL No. NS/1209/3/H/452512


GPT Masterline systems offer a cost-effective way for modem businesses to provide efficient communications throughout all levels of an organisation.

Masterline is available in three system sizes which range from eight to 24 trunk lines with up to 64 telephone users.

  • MASTERLINE 816 - 8 trunks and 16 extensions
  • MASTERLINE 1236 - 12 trunks and 36 extensions
  • MASTERLINE 2464 - 24 trunks and 64 extensions

The systems employ common hardware technology which allows for simple upgrading and also for the compatibility of instruments across the size range.

Wide Choice of Instruments
Each size offers the choice of executive standard and basic keystations. They are of a pleasing, modem design which enhances the image of any office environment, and are extremely simple to use. Dual red and green LEDs allow the status of all trunk lines to be monitored at a glance. There is also the option of approved loop dialling ordinary telephones to give cost-effective communications in areas not requiring keystation features.

System features:-

  • Handsfree Operation: enables the user to make or answer calls without lifting the handset.
  • Abbreviated Dialling: each station can access up to 90 system abbreviated dial numbers and store up to 10 personal numbers for single button dialling.
  • Do-not-disturb: permits managers to work without interruption.
  • Manager/Secretary Link: allows one or more managers to forward calls to a secretary.
  • Office Paging: The integral paging system allows staff to be located quickly to answer incoming calls or for immediate conversation with colleagues.
  • Complete Flexibility in the allocation of incoming call ringing in both the day and night service modes.

Many of the features are allocated to specific telephones through system programming and this enables the tailoring of specific facility packages for individual staff members so as to best meet their functional requirements.

Management Features
Masterline enables management to control the operating costs of the system. Six levels of outside call restriction can be applied to
individual extensions which, together with the call logging facility; cuts costs, inhibits call abuse and allows for the charging of calls on a departmental or client account basis.

Hybrid PABX Operation
As well as operating in the traditional key system mode GPT Masterline can also function as a hybrid PABX through the provision of up to two Direct Station Select (D.S.S.) Consoles at nominated operator positions.

PABX Connection
In addition to being used as a stand-alone system, Masterline can also be connected to a PABX in order to give "behind PABX working" This provides a department or specific group of employees with their own sub-communication system, whilst still allowing them access to all the PABX features.

Basic Features:-

  • Abbreviated Dialling
  • Call pick up
  • Call Restriction
  • Call transfer
  • Camp on
  • Direct Station Selection
  • Not Disturb
  • Enquiry
  • Executive Station with Display & Loudspeech
  • Flexible Ringing Assignment
  • Follow Me - Intercom and Trunk
  • Group Hunting
  • Handsfree Answerback
  • Hold
  • Intrusion
  • Intrusion Conference
  • Last Number Redial
  • Manager/Secretary
  • Message Waiting
  • Music on Hold
  • Night Service
  • On Hook Dialling
  • Paging Zones and All Call
  • Power Fail Operation
  • Repertory Dialling
  • Ring Inward
  • Ring When Free
  • Room Monitor
  • Saved Number Redial
  • Tenant Service
  • Trunk Queuing

Optional Features:-

  • Behind PABX Operation
  • Call Logging
  • Door Box
  • Extension Bells
  • External Extension
  • Headset Operation
  • Hard of Hearing Handset
  • Music on Hold - External Source
  • Private Trunk Lines
  • Tie Line Working DID Tie Lines

Taken from the GPT Brochure BR0097 (Dated 1991)


Masterline PB - Std terminal Masterline P8TXP - PF HF Exec
Masterline 12TD - 12 line Std Dual Led Masterline P12TXP - 12 line PF HF Exec
Masterline  P24TD - 24 line std Dual Led Masterline 24TXP - 24 Line PF Exec
Masterline P36D - 12 Line DSS console


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Last revised: November 05, 2022