Solution for Monitoring and Remote Control Based on Modbus RTU and S7-1200 PLC

Long distance communications in the industrial environment are a challenge for the engineering phase of a project. Not always the process to be controlled is in the same location as the control room where PLC or DCS (Distributed Control System) is installed. The solution to communicate with the equipment in the field is implemented by fieldbuses that saves cables and man hours. In this paper we propose a method to monitor and remote control a water pump trough PLC-1200 from Siemens by Modbus RTU protocol. The soft starter is located 50m distance from the control room and is connected in MODBUS RTU network through CM PtP module in ET200SP configuration. The measurement of the current in Amps is displayed on an HMI from the automation system.