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!
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!
We will now look at creating BRX Do-More dynamic web pages on our PLC web server. These pages are great for operator information display. A dynamic web page is a web page that displays different content each time it’s viewed. For example, the page may change with the time of day, the user that accesses the web-page, or the type of user interaction. There are two types of dynamic web pages.
Server Side Scripting – Web pages that change when a web page is loaded or visited use server-side scripting. Login pages, forums, and shopping carts are examples of server-side scripting. PHP, ASP, Perl, and ASP.Net, are some of the languages that can be used.
We will now look at the productivity Arduino Ethernet web server that we will implement on our Productivity Open P1AM industrial Arduino controller.
This P1AM Web Server Example is based on an example found here. This example uses the productivity open P1AM-ETH shield to create a web server that displays the input values of a P1-08SIM and P1-04THM to a web page. This page is automatically updated every 3 seconds. The IP address of the webserver is set in the Arduino program (Sketch) Entering this IP address in your browser to view the web page. This will display the information from our Arduino P1AM on our web browser. Let’s get started. Continue Reading!
We will now look at the BRX Do-More PLC Web Server. Ethernet equipped BRX CPUs and the Do-More Designer Simulator can now have a web server. This can be accessed by any web browser using the IP address of the BRX Do-More CPU.
A web server is server software or hardware dedicated to running this software, that can satisfy client requests on an Ethernet network. A web server can contain one or more websites and websites can have several web pages. A web server processes incoming network requests over HTTP and several other related protocols.
The website built into the BRX Do-More has several different tabs that have basic information about the system, status information like warnings and errors, input and outputs, system logs, user logs, and user pages. We will be enabling the webserver on our BRX Do-More PLC and showing the information that is available. This is a great tool for troubleshooting the PLC as you will see. Let’s get started. Continue Reading!