Case study of a railway operator that controls and monitors its train carriages. A light sensor makes the PLC open or close the light circuit, a temperature and humidity sensor starts the ventilation and/or the air conditioning out of range, and a voltage sensor measures the energy consumption of the wagon. The energy data goes to a control unit over the mobile network and waits on board while there is no coverage. The original installation used an M-Duino 54ARA with an integrated GPRS module. The PDF shows the system built today with an ESP32 PLC 57R and a 4G LTE-M board.

The PDF covers the challenge, the three loops (light, climate, energy), the system architecture with the signal list and the hardware. Interactive version: railway carriage monitoring case study online.