ST950S Plus+ Installation and Commissioning Manual
10.3.3. Controller Switch
This is included in the Master Switch panel and removes power from the equipment rack and
equipment powered from it. This is a single pole switch so does not provide safety isolation. If there is
an adjacent expansion cabinet, mains 230V power to the expansion cabinet is NOT removed by the
Controller Switch in the main cabinet. Also note that the maintenance socket is still powered when the
controller switch is off, as is any equipment powered from Aux MCBs.
10.3.4. Main CPU Card LEDs
When the controller is initially powered up, it performs various internal checks before starting normal
operation. While these checks are being performed, the green heartbeat LED flickers and the red
system error LED remains illuminated on the CPU Card.
If these tests fail, it would point to a serious fault on the CPU Card and it should be replaced. The error
message is repeatedly written to the handset display at 1200 baud, and no other handset operations
can take place. See the ST950 Family Handset Handbook for full details.
If the SE (System Error) light is on, then the processor will have shut the system down and logged a
fault – check the fault log.
10.3.5. I/O card LEDs
If a major fault is indicated, check that the GSPI comms cable is correctly fitted and the card address is
set correctly. If this does not solve the problem, replace the card.
If all of the LEDs on the card are out, then check that the GSPI comms cable is correctly fitted.
Also check other I/O cards in the system and the Intelligent Detector Backplanes.
If all lights are off to all IDBs and I/O cards, then suspect the +24V DC supply from the PSU has failed.
Check the +24V DC output from the PSU. If it is not present, remove the power plug into the CPU Card
and re-test – if it is then present, then suspect a short-circuit between the PSU and the I/O cards.
Remove the high-speed serial cables in the controller to isolate the short-circuit.
If there is no +24V DC available at the PSU, then check the AC mains input to the PSU. If present,
replace the PSU and re-test.
If the lights are out on only one I/O card, then the power supply on that card may have failed – replace
the card and re-test.
10.3.6. Intelligent Backplane Controller
If all LEDs on the card are out, then follow the same checking as for the I/O card.
10.3.7. CIC Card LEDs
Refer to section
for information.
Each CIC card is equipped with 6 LEDs indicating the state of each CPU.
If a major fault is indicated (fault LED illuminated), check that the GSPI comms cable is correctly fitted
and the card address is set correctly. Additionally, check that the data communications to the on-street
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