Beckhoff Kiln Controller
Production-grade gas kiln automation using a Beckhoff CP6606 PLC, Siemens LME burner management, Belimo proportional valve control, and InfluxDB/Grafana telemetry via a custom ADS ↔ ESP32 bridge.
A redesign of the Gas Kiln Control System using industrial-grade hardware. After several years of iterating on ESP32-based controllers, this generation moves to a Beckhoff CP6606 running TwinCAT 3 — giving the kiln proper recipe management, certified burner safety, and proportional gas modulation in a single coherent platform.
System Overview
The CP6606 panel PC handles the full control loop: it starts and stops burners via the Siemens LME burner management units, reads safety interlocks, and modulates gas flow through a Belimo 4-20 mA proportional valve. TwinCAT's built-in PID blocks and hardware configuration tools make the recipe and alert logic straightforward to implement and tune.
Telemetry: ADS ↔ ESP32 Bridge
The CP6606 runs Windows CE, which has no native database connector. To keep the InfluxDB/Grafana telemetry stack from previous generations, I integrated an ESP32 acting as an ADS client using EspAdsLib. The ESP32 polls process variables from the PLC over ADS (Beckhoff's native protocol), then forwards them to InfluxDB. Grafana OnCall handles alerting — firing an alert if temperatures deviate from the expected profile.
Safety System
A significant portion of the project was bringing the kiln up to safety standards. The Siemens LME burner management unit provides a certified implementation of the critical safety functions — the PLC monitors interlock status and receives feedback signals, but the decision to cut power to the safety shutdown valves is made by the BMS directly, not by software. This keeps the safety logic in hardware, independent of the PLC program.
- Flame monitoring — flamerod sensor on each burner, supervised by the LME units
- Gas pressure interlocks — low and high pressure switches on the gas train
- Air pressure interlock — low pressure switch on the combustion air supply
