|PXML No. BABT/PXML/23 SCR.0104
APPROVAL No. NS/3841/23/L/601468
The SDX 420N is a self-contained, pre-programmed key telephone systems. The systems have an integral self-test diagnostics routine which continually monitors the system, any resulting reports enabling rapid fault location and repair.
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 (change controller or PC based communication programme) and by the user (using a system manager terminal) during the lifetime of the system.
The main items for use with the systems are the basic FT-1 terminal, the feature and display FT-2, FT-3, FT-4 and FT-5 terminals, the DSS/BLF Unit, and the Operator Console. The System Manager Terminal (an FT-4 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 computer range of facilities.
The SDX 420N system comprises a Central Control Unit (CCU), up to seven Group Control Units (GCU) and up to two Extension Control Units (ECU) per GCU. A system can be sub equipped at installation and expanded to the maximum 420 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 analogue exchange lines allowing incoming or outgoing calls to be made.
Interconnection between the SDX and the analogue PSTN, Speechband 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).
Capacities Maximum System Capacities Control Each of Two Unit (SDX 60) Extension or GCU (SDX42ON) Control Units Analogue Exchange Lines 10 10 Private Circuits (DC5/10) 10 10 Private Circuits (AC15) 20 20 Power-fail Telephones 5 5 Key Stations 20 20 2-Wire Instruments 20 20 2 MBit Private Circuits 4 0 (Total 120 Channels) 2 MBit Public (DASS II) Circuits 4 0 (Total 120 Channels) Maximum Control Unit Module Capacities Trunk Card 5) 5) AC15 Card 10) 10) DC5/DC10 Card 5) 5) FSC PBA 10)Total 10 10)Total 10 Subscriber Line Card 10) 10) 2-Wire Card (39UPB20001AMW) 5) 5) 2-Wire Card (39UPB20001BMW) 10) 10) Four Wire Interface Card 9 10 Analogue Signalling Card 4 0 Operator Console Line Card 10 10 DSS/BLF Interface Card 6 6 (System Total 6) Music on Hold Card 1 0 Digital Trunk Line Cards (DPNSS or DASSII) 4 0
SDX 420 Socket Wiring
Twisted pair cable must be used and telephone extension leads must not be used.
Card Handle Colours
Last revised: November 12, 2021