How to Control Signals in Sessions
The screenshots shown below give examples of how signals can be controlled in sessions.
Application 1: Fixed Signals
1. The Scenario:
It is after hours and all the signal staff on a single track branch line have clocked off for the night. All approach and depart signals on the line are locked at PROCEED and safe working is now the responsibility of the train crew. The signals will not reset to STOP when passed by a train.
2. Rules Used:
- Ordered List Rule creates a "container" for all the Set Signal Extended rules.
- Set Signal Extended Rule to set signals to the required state. This rule can only set a single signal at a time.
3. Session Rules Screenshot:
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4. Example Explanation:
- Line 1: Ordered List Not absolutely necessary but it places all the Set Signal Extended rules in a single container
- Line 2: Set Signal Extended The first signal along the route is fixed at PROCEED
- Line 3: Set Signal Extended The next signal along the route is fixed at PROCEED.
...and this is repeated for all the signals along the route.
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When the Set Signal Extended Rule is opened for editing (shown left):-
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Application 2:
1. The Scenario:
A train approaching the home signal before a yard must come to a complete stop before the signal is changed from STOP to PROCEED.
2. Preconditions:
- Set Signal Extended Rule to initially set the signal to STOP.
- This scenario uses the Directional Trigger from the DLS to make sure that only trains approaching the Home signal will trigger the rule. Trains leaving the yard will not trigger the rule.
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3. Rules Used:
- Directional Trigger Check Rule to trigger the event for trains approaching the signal.
- Wait on Train Stop/Start Rule to trigger an event when the consist stops moving.
- Wait Rule to wait a set time interval.
- Set Signal Extended Rule to clear the signal after the train has stopped.
4. Session Rules Screenshot:
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5. Example Explanation:
