PXML No. 23 scr.0104
APPROVAL No. NS/3841/23/L/601468 was NS/2334/23/L/601468

Introduced around early 1990.

The SDX 60 is a self contained, pre-programmed key telephone system. The system has an integral self-test diagnostics routine which continually monitors the system, any resulting reports enabling rapid fault location and repair.

Although looking similar to the SDX40/180 the SDX60 has enhanced software that is substantially different.

Systems when delivered are in full working order with all standard features and facilities incorporated. On completion of installation a simple self-diagnostic test procedure enables the system to be proved before handover.

A simple change procedure enables features and facilities to be altered following installation and by the user during the lifetime of the system.

The main items of the system are the Control and Extension Control Units, the basic FT1 terminal, the feature and display FT2, FT3, FT4 and FT5 terminals, the DSS/BLF Unit, and the Operator Console. The System Manager Terminal (an FT4 terminal with a mask placed over the keys), a VDU with keyboard (VT100 compatible), or the Change Controller enable features and facilities to be changed as required.

The Change Controller and the VDU also provide the maintenance engineer with diagnostic tools. The complete range of features is only available when using a VDU which also aids programming. Alternatively, a personal computer (PC) may be used off line to program the SDX range of facilities using any communications package that supports VT100.

The SDX60 system configuration of one Control Unit and two Extension Control Units supports up to 60 devices, a device being an external line (trunk or tie line) or an extension. A system can be sub-equipped at installation and expanded to the maximum 60 ports at a later stage.

The Change Controller/VDU connection to the system is via one of two RS232C compatible ports which can also be used to connect an optional, customer supplied printer. This can then be set up to provide a paper printout of call or fault statistics.

A power-fail feature enables one or more standard telephones to be connected to the system, in the event of a power failure these are connected directly to the exchange lines allowing incoming or outgoing calls to be made.

Interconnection between the SDX and the PSTN, speech and private circuits or host CRA is via BT 239A connectors on the connector block located inside the SDX Control Unit and Extension Control Unit. Alternatively, a separate Test Jack Frame may be used comprising a suitable connection box with BT 237A connection strips, connected within 15 metres of the SDX system.

The apparatus is also approved for use in the Simple Call Routing Mode (SCRM).

SDX 60 Socket Wiring

LJU 2/3A Wire colour MDF termination
2 Blue/White 4
3 Orange/White 2
4 White/Orange 3
5 White/Blue 1

Twisted pair cable must be used and telephone extension leads must not be used.

Card Handle Colours

Handle colour Card Type
Yellow 2cct Subscriber Line Card (SLC - Terminal)
Brown 1cct or 2cct SLT Card (two wire POT or TAMS) 
Blue 2cct LD Trunk Card
Pink 2cct LD/MF switchable trunk card
Orange DC5
Green 2cct MF trunk Card
Black AC15 or DASS/DPNSS Card
Purple DSS Card, supports one key phone port and one DSS port

Two Wire Card information


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Last revised: November 12, 2021