Userpages - Hermann (hermannk) → Double Track Crossing 1

Foreword 1:
This documentation was created with this: Status 02/13/2023

Foreword 2:
- the use of this solution is at your own risk;
- regular backups of the Rocrail workspace are recommended.

A two-track railroad crossing is to be provided with a barrier control that also includes the control of a two-lane road.
It should be possible to drive on the tracks both individually and simultaneously.
There is no prioritization regarding track or road.

In this solution example there are:
- two tracks; they are only used in one direction;
- two streets; they are only used in one direction.
Accordingly, four level crossings are applied: "swbu11", "swbu12", "swbu21", "swbu22".

A level crossing is a "switch" of type "accessory" with the accessory number 10, 11 or 12.

The level crossing is closed to automobiles at "straight".
The level crossing is open to automobiles at "turnout".
In this documentation, each level crossing has an optically visible barrier arm to make the commands for each of the level crossings visible. In the working area only the level crossings "swbu12" and "swbu22" have a barrier arm.

The four possibilities when locomotives are running (the routes marked in yellow are used):

	none	below	above	both
switch	position, status	position, status	position, status	position, status	the locomotives are running
swbu22	turnout, unlocked	straight, unlocked	straight, locked	straight, locked	the automobiles are waiting
swbu21	turnout, unlocked	straight, unlocked	straight, locked	straight, locked
swbu11	turnout, unlocked	straight, locked	straight, unlocked	straight, locked
swbu12	turnout, unlocked	straight, locked	straight, unlocked	straight, locked

As soon as a route for locomotives is provided, the routes for automobiles are blocked.

The four options when automobiles are driving (the yellow-marked lanes are used):

	none	left	right	both
soft	position, status	position, status	position, status	position, status	the automobiles drive
swbu22	turnout, unlocked	turnout, locked	turnout, unlocked	turnout, locked	the locomotives are waiting
swbu21	turnout, unlocked	turnout, unlocked	turnout, locked	turnout, locked
swbu11	turnout, unlocked	turnout, locked	turnout, unlocked	turnout, locked
swbu12	turnout, unlocked	turnout, unlocked	turnout, locked	turnout, locked

As soon as a route for automobiles is provided, the routes for locomotives are blocked.

When dissolving a route over the level crossing, the points should be set again,
- but for locomotives only if the opposite direction is also free and
- for automobiles, the switch position can remain unchanged.

Usually the points are opened again when the route is released (unlocked). In this example, this is also done for the locomotives, but only for the turnouts in their own direction of travel!
In the case of oncoming traffic, the points in the opposite direction remain closed, so that the level crossing remains closed to automobiles.

In the following table, the lower road was set and is now resolved; two cases have to be considered:

	before below	after none	-	before both	after above
switch	position, status	position, status	-	position, status	position, status
swbu22	straight, unlocked	turnout, unlocked	-	straight, locked	straight, locked
swbu21	straight, unlocked	turnout, unlocked	-	straight, locked	straight, locked
			-
swbu11	straight, locked	turnout, unlocked	-	straight, locked	straight, unlocked
swbu12	straight, locked	turnout, unlocked	-	straight, locked	straight, unlocked

Special treatment for routes for locomotives: the barriers may only be opened if the opposite direction is free.
In this example resetting the points
- for the lower route by actions and
- for the upper route by calling an XML script.

In the following table, the left route was set and is now resolved; two cases have to be considered:

	before left	after none	-	before both	after right
switch	position, status	position, status	-	position, status	position, status
swbu22	turnout, locked	turnout, unlocked	-	turnout, locked	turnout, unlocked
swbu21	turnout, unlocked	turnout, unlocked	-	turnout, locked	turnout, locked
			-
swbu11	turnout, locked	turnout, unlocked	-	turnout, locked	turnout, unlocked
swbu12	turnout, unlocked	turnout, unlocked	-	turnout, locked	turnout, locked

No special treatment is required for routes for automobiles.

In the lower route "[bk11+]-[bk12-]" dissolving the route is demonstrated by actions:
An action was created for each point:
- "ac_turnout_swbu11"
- "ac_turnout_swbu12"
- "ac_turnout_swbu21"
- "ac_turnout_swbu22"
Definition of the action:

The action is called in the route "[bk11+]-[bk12-]" if it is released (status = unlocked), but only under the condition that the opposite direction is free (route "[bk21+]-[bk22-] " unlocked).
Application of the action:

The "Timer = 100 ms" ensures that the point has already been released so that the point can now be set by the action.

In the upper route "[bk21+]-[bk22-]" dissolving the route is demonstrated by an XML script; For this purpose, the action "ac_route_state_unlock" was created, which calls the XML script "ac_route_state_unlock.xml".
Definition of the action:

The action is called in the route "[bk21+]-[bk22-]" when it is released (status = unlocked);
- the condition is encoded inside the XML script:

<if state="st [bk11+]-[bk12-] = unlocked">

Application of the action:

A "Timer = 0" is sufficient because enough time is consumed to process the XML script.

- only a virtual simulation was carried out with "Start all locomotives virtual";

- warnings and errors occurred during the simulation; examples from the trace file:

... r9999E tr01 OSwitch 0928 Switch [swbu12] pending operation for lock route [[bk61+]-[bk62-]]
... r4104W tr01 OLcDrive 0088 Could not lock route "[bk61+]-[bk62-]", for "tr01"...

- in principle, warnings occur for the routes for locomotives; this is normal for this solution; examples from the trace file:

... r9999W lc02 OSwitch 1286 switch [swbu12] is locked by [lc01]: reject any commands from others

The good thing:
- locomotives and automobiles have never met on the level crossing.

The download workspace "doubletrackcrossing1.zip" contains the following files:

back to the solution-details.

You are welcome to implement your own ideas on the basis of this solution.
Have fun and good luck.