For controlling the signal lights and the acoustic warning device of an automatic warning system used to secure a track construction site. The LEDs or lamps for the signal lights blink asynchronously as long as the module's switch input is closed. The warning tone is played for the duration set on a trim pot on the module after the switch input is closed. Note about the stored sound: The LC-NG module is not designed as a sound module; the stored sound is correspondingly simple.