Tag Archives: node-red plc modbus

Do-More PLC Node-RED HTTP Request


Node-RED HTTP Request can be used to read any BRX Do-More PLC memory area. This HTTP (Hypertext Transfer Protocol) communication will only read information from our controller.

The BRX Do-More REST API is used to read information using a URL (Uniform Resource Locator) or web address. We will be using the HTTP request node in Node-RED to read information from our BRX Do-More REST API-enabled controller. Writing using Modbus will also be shown. This will all be done on our Raspberry Pi 4 single-board computer. Let’s get started. Continue Reading!

Node-RED User Interface – Dashboards


Node-RED can easily display interactive information to the user or operator using a web browser on your phone, tablet, or computer. Any device that has access to the network in which node-red is running.
We will be installing the node-red-dashboard palette. This allows us to create a live data dashboard user interface. (UI)

The information from our Solo process temperature controller will be displayed. Setpoint information can be set either by the dashboard UI or the Click analog input signal. This will be selected via the user interface. Let’s get started using Node-RED Dashboards. Continue Reading!

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 the commands to read or write to the slaves on the network. The slaves will respond if the communication 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. Continue Reading!

Node-RED Installing the Windows Software


We will now be installing the Node-RED software on our Windows 10 computer. Node-RED is a powerful and easy programming tool that will allow you to join together hardware devices, APIs (Application Programming Interface), and online services. This joining of information is part of the smart factory. Internet of Things (IoT), Industrial Internet of Things (IIoT), Industry 4.0, and Smart Production are just a few of the other labels that have been applied to this type of technology.

Node-RED provides a browser-based flow editor. This provides an easy way to visually see and modifies your program flow. Flows can then be deployed to the runtime in a single click. Node-RED is built on Node.js. This lightweight runtime can be deployed on low-cost hardware (Raspberry Pi ) or cloud services (Microsoft Azure). This has the ability to bring data collection, analysis, and storage closer to the actual device. Real-time edge computing can then be achieved without latency issues.

In this series we will be using Node-RED in some of the following ways:
– Connect to our industrial equipment using the Modbus protocol.
– Display Information on a user interface, HMI, or dashboard
– Log information into a database
– View information in the database through spreadsheets such as Excel.
Let’s get started by installing Node-RED. Continue Reading!