Node-RED Modbus RTU / TCP Communication

Node-RED can easily connect to industrial controls using Modbus communication. Modbus is a master-slave type of communication. Masters will always send commands to read or write to the slaves on the network. The slaves will respond if the transmission is directed at them. We will be installing the node-red-contrib-Modbus palette. This will allow us to communicate Modbus serial (RS485) RTU to a Solo process temperature controller. We will then use Modbus Ethernet TCP to communicate to a Click PLC. Note: When using Modbus TCP (Ethernet), the master is referred to as the Client, and the slave is a Server. Node-RED will be used to create a single Modbus flow. We will communicate to our Solo process temperature controller using Modbus RTU on a serial RS485 network. The present and set values of the controller will be read. These values will then be written to our Click PLC using an Ethernet Modbus TCP network. A set value from an analog input on the Click will be used to then write to the Solo. This will happen every 200 milliseconds or 5 times per second. Let’s get started using Node-RED for Modbus communication. In this series, we started using Node-RED in some of the following ways: Installing the Windows Software https://accautomation.ca/node-red-installing-the-windows-software/ Video https://youtu.be/xGzH2Hv31WA We will continue with the following: Connect to our industrial equipment using the Modbus protocol. Additional information can be found on our website at the following URL: https://accautomation.ca/node-red-modbus-rtu-tcp-communication/ Future information will include the following: Display Information on a user interface, HMI, or dashboard Log information into a database View information in the database through spreadsheets such as Excel. 00:00 Node-RED Modbus Click PLC and Solo Process Temperature Controller 02:06 Installing node-red-contrib-modbus Palette 04:05 Node-RED Modbus Flow Program 09:06 Solo Process Temperature Controller - Modbus RTU 09:45 USB to RS485 Converter Settings 10:34 Hardware Click PLC, Solo, USB to RS485 Converter 12:15 Click PLC Modbus TCP Settings 14:30 Click PLC Modbus Addresses 15:03 Node-RED Modbus RTU TCP Flow Program Example There are several reasons why we are using Node-RED. Here are just a few. - Built on top of the most dependable programming language, JavaScript. - JavaScript is flexible and easy to work with on web browsers, server-side, IoT, IIoT projects, and more. - Visual flow type interface making programming easy. - Node will allow JavaScript code to run directly on a computer. - Node-RED is a free, open-source logic engine. - Connect to PLC, PAC, Temperature Controllers, and Process Controllers using standard protocols. - Save and read from databases - Easily make the Internet of Things (IoT, IIoT) industrial solutions. Node-RED provides the ability for you to quickly create custom control solutions. ACC Automation https://accautomation.ca/