Scripts exist in functions, triggers, and timers. They define a sequence of simple commands that are executed when the action takes on a certain state.
Scripts are made up of the following simple commands:
- pin[]: Set an output pin to a certain value.
- param[]: Set a parameter to a certain value.
- pause(): Wait for a few milliseconds.
- call(): Invoke another action in the same CTC module, e.g. a timer.
- if(): Execute the commands under “if” only if a parameter has a specific value.
In the script for a driving order, there is an additional command
- on XXX: The locomotive should pass the balise XXX and possibly execute a command - see Chapter 7.3 - Driving Orders
When the state of an action changes depends on the type of the action:
- Functions and value controllers are changed by the user of the CTC app by pressing a corresponding button or adjusting a slider.
- Timers are triggered once after a certain time or at regular intervals automatically by the CTC module.
- Sensors are triggered via switches. These can be pressed by a person, or triggered by a locomotive or wagon while passing by.
- Triggers trigger as a result of another action. Triggers can be functions and value controllers, as well as sensors and IDs read by locomotives.
The top level of the script determines how the action should react to which values. In the value-config, the actions are defined that are possible for a function (they are part of the cfg.xml). For example, for a locomotive’s light, the four actions:
- off
- on
- front
- back
can be defined.
For each action, you can specify which of the outputs defined in the IO-config should be switched. This is often only a single output, but it can also be a sequence with conditions, as the example dialogue for the action straight of the turnout PI-Dev-LH5 shows.
For turnouts, note that the icon displayed in the turnout list is determined by the name of the action. The position (0 to 2) indicates the column in the turnout view:
| Function | Name of the Action | Character | Icon | Recommended Position |
| Left Turnout | left_left | l |  |
0 |
| left_straight | s |  |
1 | |
| Right Turnout | right_straight | s |  |
1 |
| right_right | r |  |
2 | |
| Three Way Turnout | three_left | l |  |
0 |
| three_straight | s |  |
1 | |
| three_right | r |  |
2 | |
| Cross Turnout | cross_notcross | x |  |
0 |
| cross_cross | n |  |
1 | |
| Four Way Cross Turnout | cross_hor | h |  |
0 |
| cross_vert | v |  |
1 | |
| cross_left | l |  |
2 | |
| cross_right | r |  |
3 |
Commands for Locomotives / Signals
The following commands can be interpreted by locomotives when they are linked with a balise:
| Function | Sign | Meaning | cmdDist | Description |
| Stop (Hp0 / red) | ‘H’, ‘h’ | Indication of an upcoming red signal. | Distance | The locomotive decelerates and stops before this signal. If the signal turns green again, the locomotive resumes its journey and accelerates to the maximum permissible speed according to the signal image. |
| Go (Hp1 / green) | ‘F’, ‘f’ | Indication of a green signal. | Distance | Any previous speed limit is hereby repealed. Nothing happens in manual control, otherwise the locomotive accelerates to its maximum speed. |
| Slow approach (Hp2 / green+yellow) | ‘W’, ‘w’ | Indication of slow travel. | Distance | If the locomotive is too fast it decelerates to a reduced speed, e.g. to not derail over a diverging turnout. |
| Speed limit | ‘L’, ‘l’ | Indication of a speed limit. | Speed | If the locomotive is too fast, it brakes to this speed. The distance is multiplied by 10 and interpreted as speed. |
| Minimum speed | ‘M’, ‘m’ | Indication of an upcoming red signal with a second balise for the final stop. | Distance | The locomotive slows down to a crawling speed. The second balise in front of the signal then sends Stop with distance 0 cm or Emergency Stop. |
| Emergency Stop | ‘E’, ‘e’ | Emergency stop, e.g. shortly before the track end or signal. | Distance | The locomotive stops abruptly. If the signal turns green again, the locomotive resumes its journey and accelerates to the maximum permissible speed according to the signal image. |
| Stop | ‘S’, ‘s’ | Indication of an upcoming stop according to schedule. | Pause in seconds | In automate mode, the locomotive stops, waits for the break time, and then continues its journey. From CTC-App 4.08: In manual operation like protective stop with distance 0. |
| Reverse travel | ‘R’, ‘r’ | Indication of an upcoming stop at the turning point of the timetable (shuttle train). | Pause in seconds | In automate mode, the locomotive stops, waits for the break time, and then continues its journey in the opposite direction. From CTC-App 4.08: In manual operation like protective stop with distance 0. |
| Protective stop (Sh2) | ‘T’, ‘t’ | Indication of the track end, e.g., buffer stop. | Distance | The locomotive decelerates and stops in front of this sign. |
Almost every command is associated with a distance in cm from which this command applies. The locomotive calculates its braking distance to suit this distance, e.g., “Stop” with distance “65” results in the locomotive stopping after 65 cm.
Note: A prerequisite for functioning target braking is a correctly calibrated motor sensor (see chapter “Calibrate Motor Sensor”)
The commands can either be permanently stored at the balise or dynamically changed using “triggers”. For example, one can link a balise with the status of a signal (see chapter “Config - Link Actions”). Therefore, you should use the same letters for signal states as for the corresponding locomotive command.