Page 8 of 29
BLOCKsignalling www.blocksignalling.co.uk
Program 2 - Fiddle Yard
A fiddle yard has a queue of trains. When the one at the front of the queue departs
each of the trains behind move up one position in the queue.
In the drawing below, we are just showing one train, which is stationary at location A
(due to the module not powering the isolated section of track). This train has arrived
from the right and stopped once it was unable to pick-up power from the track.
If the operator presses the push button (connected to the TRIG terminal), the module
will start to follow a built-in program. In this case, one of the relays on the module
will energise, and this will allow power to flow to the isolated rail and the loco will
move towards the left, entering the powered section of track (B).
When the loco reaches the sensor at C the train is detected and the relay on the
module de-energises making the isolated section dead again, preventing any other
locos entering the section.
The loco carries on until it reaches the isolated section at D. It will stop and wait
here until this section is powered from elsewhere.
At the point the train is detected at C, the module sends out a signal out on its
"DONE" terminal, so the sensor should be close to the isolated track at D. If this is
not possible, a delay can be programmed so that the DONE signal is not sent until
sometime later.
In this case, we have not made a connection to the DONE terminal yet as we are
only showing one module.
