Low-cost multifunction controller prototype for sawmill wood processing

Abstract

The paper presents concepts and implementation of a small multifunction controller. The device has been designed to control and monitor wood processing in a sawmill. It runs three control tasks simultaneously, namely climate control, drying control, surveillance system, and one HMI (Human-Machine Interface) task. CPDev environment has been used to develop programs in IEC 61131-3 LD, ST and SFC languages. Control algorithm of the drying process with SFC and ST is presented in more detail. CPDev virtual machine executes the tasks concurrently on the controller. Programmable graphical operator HMI created with the CPVis tool is also handled by the controller. The prototype employs the well-known Raspberry Pi 2 platform, reducing costs of the device.