Click Plus PLC MQTT Communication

We will now look at the MQTT communication capability using our Click plus PLC. MQTT stands for Message Queuing Telemetry Transport. This simple, publish, and subscribe communication protocol does not take too many resources. Constrained devices with low bandwidth are ideal for MQTT. This protocol provides machine-to-machine (M2M) connectivity which is ideal for the Internet of Things. (IoT) This protocol is not for remote IO or real-time (deterministic) applications. MQTT is a good solution for applications that move data from hundreds or thousands of machines (sensors) to clients in many networks. We will be installing a windows based broker called Mosquitto. The Click Plus PLC will be one of the clients publishing and subscribing to the MQTT broker. Node-RED will be the other client publishing and subscribing to the MQTT broker. Each client will share information. Let’s get started. The Click Plus can only be programmed with version 3.00 or higher of the Click Programming Software. Version 3.00 will program all of the Click PLC CPU units and add additional features to the Click Ethernet CPU units. Features of the new Click PLUS PLC (C2-0xCPU) includes the following: • Micro USB • DHCP support • DNS support • Wi-Fi (programming and Modbus TCP) • Bluetooth (Wi-Fi) provisioning • SD Card (Data Logging) • Data Logger • Network Time Service • MQTT (Publish/Subscribe) • Required PLC Password • Disable Ports • Strong Password Support • Disable Ping Response • Encrypted Password Transfer