“Applying IoT Technologies to revive an old SCADA Telemetry System
I took up a challenge from an oil/gas client to revive a GSM based SCADA system that they had inherited, and to do so at very low cost. The existing RTUs at the remote sites used GPRS which is no longer available. 3G, however, is available at all sites. Fortunately, the existing RTUs have the ability to be programmed as Modbus RS485 slave devices. So the solution is to use the Arduino MKR 1400 to interface with the existing RTU devices and then have them connect to a cloud service and send MQTT updates. At the base, Node-Red will be used to connect to the cloud service and subscribe to the data points and expose them to the HMI which is a very old version of Wonderware Intouch. The diagram below shows the proposed set up.”