Trigger placement for ATLS LCM

davidakridge

Session Creator
In the picture, the red boxes are level crossings and the arrow shows a switch to a spur line. I need an idea of placing triggers for the crossings. The way I see it they will have to be next to the crossings because if I put the triggers for both crossings before the switch, both crossings will light up and close no matter which direction the switch is thrown.

I was wanting suggestions on how others would set their triggers for this scenario.

David

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I've been playing with ATLS LCM recently...

As I see it there are two options.
1- Place atls triggers just after the switch, then only when the train has taken the route to the crossing will it operate. You can increase the radius of the triggers so actually they fire earlier. Place in Tracks>Trackside, modify in Tracks>Trackmarks and triggers>Advanced.
Or (this is probably better)
2- Don't place triggers at all. Place a trackmark just after (assuming you're running trains from right to left) the right-most crossing. In the session, set up the Driver Schedule for mainline trains to be Drive via trackmark/ATLS Trigger Command Channel 1/Drive to next trackmark and for branch trains to be Drive via trackmark/ATLS Trigger Command Channel 2/Drive to next trackmark.
There is also this rather clunky option
3 - Make the junction just after the first crossing, with invisible track on one branch to the site of the real junction. Place your triggers on this track.
You will still need clearing triggers on the tracks after the crossings in any of these options.

Hope this helps.
 
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I like to use train priorities for situations like this, this feature doesn't get enough credit. Regular trains keep their default priority 2, but local freights get 3. Mainline trains don't trigger spur crossings.
 
I like to use train priorities for situations like this, this feature doesn't get enough credit. Regular trains keep their default priority 2, but local freights get 3. Mainline trains don't trigger spur crossings.

Does it work vise versa, does spur line trains trigger the main crossing?

David
 
I've been playing with ATLS LCM recently...

As I see it there are two options.
1- Place atls triggers just after the switch, then only when the train has taken the route to the crossing will it operate. You can increase the radius of the triggers so actually they fire earlier. Place in Tracks>Trackside, modify in Tracks>Trackmarks and triggers>Advanced.
Or (this is probably better)
2- Don't place triggers at all. Place a trackmark just after (assuming you're running trains from right to left) the right-most crossing. In the session, set up the Driver Schedule for mainline trains to be Drive via trackmark/ATLS Trigger Command Channel 1/Drive to next trackmark and for branch trains to be Drive via trackmark/ATLS Trigger Command Channel 2/Drive to next trackmark.
There is also this rather clunky option
3 - Make the junction just after the first crossing, with invisible track on one branch to the site of the real junction. Place your triggers on this track.
You will still need clearing triggers on the tracks after the crossings in any of these options.

Hope this helps.

I've read about option #2. I will pay around with it. Great input. thanks

David
 
set up each crossing as individuals (say channel 1, 2 & 3) The right hand crossing being 1 the spur 2 and main line 3. Crossing 1 normal set up, crossing 2 set up the triggers before the junction to react only on priority 3 (so remove the ticks in 1 & 2) and for the main line 3 remove the tick in priority 3. When a train wants to use the spur use the change priority driver command somewhere before it reaches the crossing. Maybe after a drive via TM command. The train will pass the channel 3 triggers without any activation of crossing 3. Like wise other trains on priority 2 or 1 will activate crossing 3 and not the spur. The train coming out of the spur will need to be priority 3 to activate the triggers but will have to change back to priority 1 or 2 after leaving the spur in order to activate the main line triggers.

In davids post the Triggers after the junction may not work as it relies on the junction being switched the correct way early or else both triggers will see the train if the junction switches late.
 
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...

In davids post the Triggers after the junction may not work as it relies on the junction being switched the correct way early or else both triggers will see the train if the junction switches late.
Of course. My mistake. I'm getting too used to using the Path Set rule & commands, which set the route through junctions very early compared with normal Drive To or Drive via trackmark commands.
 
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