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BLOCKsignalling
www.blocksignalling.co.uk
Troubleshooting
When the power supply is connected and switched on, the red led on the module
should light for 1 second, then flicker at a fast rate. This flickering indicates that the
module is looking for a train in front of the sensor.
At the same time, the green aspect of the connected signal should light.
If an object is brought close to the sensor, the red led on the module extinguishes
(as an object has been detected) and the green aspect of the connected signal
should extinguish and the red aspect should light.
The red led on the module then flashes at 1 second intervals (seven times is the
default consisting of 5 seconds for the red to be shown and 2 seconds for the
release time) and the red aspect of the signal should extinguish and the next aspect
should light. Depending on the number of aspects of the attached signal this will be
yellow (for 4- and 3- aspect signals) or green for 2-aspect signals.
For 4- and 3- aspect signals, the led on the module will continue to flash at 1 second
intervals (five times is the default) and then the yellow aspect of the signal should
extinguish and the next aspect should light. Depending on the number of aspects of
the attached signal this will be double-yellow (for 4-aspect signals) or green for 3-
aspect signals.
For 4-aspect signals, the process repeats again until finally green is shown.
During the above process, the module can still be triggered by another train, and if
one is detected, the module will immediately switch the signal to red.
Notes
1. If a 2-aspect signal is connected, and there is a gap of several seconds
between the red led extinguishing and the green led lighting, then the module
may be programmed for 3- or 4-aspect signals.
2. Similarly, 3-aspect signal is connected, the yellow led is lit for longer than
expected before the green led lights, then the module may be programmed for
4-aspect signals (the yellow led stays lit during the phase when double-yellow
would be shown on the 4-aspect signal).
3. If the module led does not light when the power is applied, then it may be a
power supply problem. Check the power supply connections are secure and
the correct polarity has been observed.
4. If the green signal led does not illuminate after the module led starts flickering,
check the signals are common-anode. Common-cathode signals will not
operate with this module. If in doubt, check with the supplier of your signals.
