A Track Trigger has two important properties:-

• its name which is needed for all commands and rules that use the Track Trigger, and
• its Trigger Radius (the green "wings" shown in the image above with the radius value, in metres, shown below the trigger name). This controls how closely an AI train has to approach the trigger to activate it (smaller radius = closer to the trigger)

A Track Trigger is placed on the track by:-

1. clicking the Track tool,
2. clicking the Trackmark Mode button,
3. selecting the Trigger object from the list of installed objects,
4. clicking the Add Object button,
5. clicking the track position where the track trigger is to be placed.

• To change the track trigger name click on the name box, delete the highlighted default name and enter a new name
• To change the assigned layer click on the layer box and select a new layer
• Leave the "Bound Layer" at <none>. (See the Trainz Wiki Page Using Layers for information on layers)
• To confirm the changes click on the icon on the bottom right of the window

1. Click the Advanced Tab to open its properties
2. Enter a new radius value in metres
3. Click the Set Trigger Radius button
4. Click on the track trigger to assign its new radius

A small radius should only be used for slower moving trains. Short fast trains may pass over a small radius track trigger without being detected.

Then select Track Objects

	Select the Placement Tool (or press the  E  key) from the Tools Palette
	Left click on the track at the position where you want to place the Track Trigger

The Track Trigger can be easily moved if needed - see below.

1. Left click on the Context Tool ( in the image on the left or press the  T  key if the asset has already been selected) to open up the object property and control menu
2. Left click on Edit Properties option
3. Enter a name for the Track Trigger

1. Select the Fine Adjustment Tool (or press the  D  key)
2. Left click and hold down the mouse button on the Blue Vertical Axis Line above the Track Trigger ( in the image on the left)
3. While holding down the Left mouse button, move the mouse Forward or Backward to move the Track Trigger Up or Down

1. Left click on its Context Tool (or press the  T  key if the asset has already been selected)
2. from the popup menu select Reattach to Track

1. click the small arrow next to the layer name. This will open the layer properties for the selected object
2. click the Layer drop down box to select a new layer for the object
3. if required, click the Binding drop down box to select a new binding layer for the object
4. if required, click the  Lock Layer  button to lock the selected layer. If the layer is already locked then this will be shown as an  Unlock Layer  button

WARNING: You will not be allowed to place a track object in a layer that is higher up the list than the layer containing the track.

• How to Use Layers

To add the Trigger Check Rule to a session:-

1. Open the Surveyor Main Menu in TANE (shown below left) or the Surveyor Edit Menu in TRS19 and later Trainz versions (shown below right)
2. Select the option Edit Session from the drop down menu list

• Click the Add button

In the Rule Selection window (shown below right):-

1. Scroll down the list to select the Trigger Check rule
2. Click on the icon

• Click the Edit button. This will open the rule properties window

In the Trigger Properties window (shown below):-

• Click the Add trigger link

1. Select the trigger you have just added
2. Click on the icon at the bottom of the selection window

1. Make sure that the new Trigger Check Rule is selected (highlighted)
2. Click the Add button to add another new rule
3. Scroll down the rule selection window to find and select the Message Popup rule
4. Click on the icon

With the Message Popup Rule highlighted:-

• Click the Indent (right arrow) button.

This should indent the Message Popup rule one level inwards (as shown below).

• Click the Edit button. The Message Popup Rule properties window will appear (as shown below)

1. Check ON Close previous message popup windows
2. Select Option Button Custom text
3. Enter a short text message

• Click the link click here to set (shown left) and either

• Scroll down the Texture Asset Selection List (shown below) to find a suitable icon, or
• Simply type "icon stop" in the text box to use one of the builtin icons.

• Click on the icon

• click on the icon to exit the Message Popup Rule and return to the Session Editor
  

The completed Message Popup Rule

• Exit the Session Editor
• Add a consist to your layout a short distance from the track trigger (but further away than its radius), save the Surveyor Session, and then test in Driver Mode