Design and Development of a Low Cost Programmable Logic Controller Workbench for Education Purposes

Abstract

As the response to the feedback from academic and industry, the department of Agricultural Engineering, Faculty of Engineering and Architecture, University of Khartoum has successfully designed and developed a low cost programmable logic controller (PLC) workbench for educational purposes. The developed bench, hardware consist of PLC (Siemens, STEP7-224XP) unit, 24V/10A DC (CE, DP177.101) power supply, personal computer, USB/PPI multi-master cable, three DIN Rail, ten pieces of 24 VDC relays, thirty jacks, thirty sockets. The selected PLC unit has tw o communication ports, fourteen inputs and ten outputs discreet plus two inputs and one output analog. Laboratory activities of the PLC workbench includes five developed modules namely replacing relays by PLC, (AND/OR/NOT) functions, latching, timer, and counter as well as packing system prototype. A Ladder diagram under Micro/Win32 software is used to run the workbench. The developed PLC workbench has a facility to be upgraded to include human machine interface (HMI), modem module, and considered as a base for new Agricultural Automation and Robotic Laboratory. The unit total cost is about 1600 US Dollars.