An Alternative Method for Communicating with a Programmable Logic Controller

Abstract Communications is the Keyword in the modern industrial automation environment and effecttive interfaces are required around a Programmable Logic Controller (PLC). In this paper a low-cost solution for communicating with a PLC is proposed. A simple printed circuit board, a small part of controller's memory and some digital outputs are the only requirements in order to achieve a low-level communication with a PLC. The method has been implemented and tested in a real environment of PLCs