Method	Description
getState()	Gets the signal state
isForcedRed()	Checks if the red signal is locked
setForcedRed(forced)	Locks/Unlocks the red signal
getSignalType()	Gets the signal type
cycleSignalType()	Switches the signal type
listBlockingTrainNames()	Lists trains triggering the signal

Event	Description
train_signal_state_change	Triggers whenever the signal changes

---

getState()

Gets the train signal's currently displayed signal, as how the trains see it.

Returns

• string The color of the signal currently displayed - either "RED", "GREEN" or "YELLOW" (Only on CROSS_SIGNAL types).

isForcedRed()

Checks if the signal is forced red by the computer.

Returns

• boolean The state of the computer-controlled red light.

setForcedRed(forced)

Forces the signal to be red regardless of redstone and free space ahead.

Goes back to default behaviour when losing connection with the computer.

Parameters

• forced: boolean enable/disable forced red mode.

getSignalType()

Gets the train signal's signal type (Normally toggled with a wrench) as how the trains see it.

Returns

• string The signal type - either "ENTRY_SIGNAL" or "CROSS_SIGNAL".

cycleSignalType()

Cycles through the train signal's signal types like if you used a wrench on it.

listBlockingTrainNames()

Retrurns

• table List of train name strings occupying the track.

---

Events

The following are events that can be accessed with os.pullEvent(filter).

Event: train_signal_state_change

Triggers whenever the signal changes.

Returns

• string Position of the signal that triggered this event, relative to the computer.
• string Name of the signal it switched to, either "RED", "GREEN" or "YELLOW" (Only on CROSS_SIGNAL types).

Example

Print what signal has changed to what state in the terminal.

while true do
    local event, side, status = os.pullEvent("train_signal_state_change")
    print("Signal on side", side, "changed to", status)
end