26- IoT Masterclass, Part4: MQTT Communication in Siemens Unified HMI Panel using Node-Red Edge App

[@YoussefBachiri]

Can you try reading and writing the PLC's variables using MQTT and visualizing them in Node Red Dashboard ? Thank you

[@blociot]

Hi Youssef. Yes you can do it with new Unified Comfor Panels. If you use an Ololder HMI which doesn't support Edge apps, you can imolement the data interaction in your PLC and show them on your HMI. Our previous video (Part 3 of IoT masterclass) shows how to connect a PLC to a MQTT broker.

[@YoussefBachiri]

But how can I subscribe or Publish to more then one Topic? As a Dashboard i want to visualize the Variables on the Node-red Dashboard

[@blociot]

@@YoussefBachiri you just need to copy and paste the set of nodes that I showed to subscribe to the example tag.

[@YoussefBachiri]

@@blociot yes, I did that, but if I publish from the PLC then the subscribe topic is overwritten directly and the topic is shown by publichen in subscribe

[@YoussefBachiri]

@@blociot yes, I did that, but if I publish from the PLC then the subscribe topic is overwritten directly and the topic is shown by publichen in subscribe