10.2.5 LSLS Card LEDs
Refer to Table 10 on page 59.
Each LSLS card is equipped with 32 multicolour LEDs indicating the state of each
output.
It should be remembered that for pedestrian phases, the amber channel is used for
the pedestrian wait indicator, and hence may be lit for relatively long periods giving
the false impression of being stuck red and amber.
10.2.6 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 LPU has failed.
Check the +24V DC output from the LPU. 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 LPU 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 LPU, the check the AC mains input to the
LPU. If present, replace the LPU 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.
10.2.7 Intelligent Backplane Controller
If all LEDs on the card are out, then follow the same checking as for the I/O card.
10.2.8 Audible Driver Module – Single Output type
The green PP LED on the Audible Driver Module will only illuminate when the
audible indicators are being driven. This will only occur when the LSLS output is on
(i.e. -48V DC) AND the inhibit+ and inhibit– connections on the module are shorted
together AND the output is not short-circuited.
If the green PP led is ON but the audibles are not sounding, check the polarity of
the audible connections to the module and re-test. Measure across the “Audible +”
and “Audible –” connections of the module - the module will present 12V DC when
driving the audibles. If this is present, then suspect the connection between the
module and the audibles and check that the audibles are not faulty by substituting a
known working audible.
Remove all audible connections to the module. If the PP LED on the module
illuminates when the audibles should sound, check for a short-circuit on one of the
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