Node-Red to HMI connection


#1

I am trying to determining if there is a way to write data directly to a manufactured HMI that is capable of Modbus TCP/IP communications. I want to display values that are stored in an SQL database for example, on the HMI screen. There would be no PLC in this system. Is this possible?


#2

If it works as a modbus slave that you can send modbus data to that gets displayed then it should be possible using one of the modbus nodes. I am not certain from your description whether it does function like that though.


#3

Sorry, is believe it is a slave in that regard? I am able to get modbus register data displayed to this HMI from other devices on the same network...for example I have a small Advantech unit counting pulses, and I can display the total number of pulses collected to this HMI screen. (Register 40002 for example) That device is set up with an static IP address and using port 502.


#4

I think that means that the HMI is a modbus master, and asks the other devices for data which gets displayed. Is that right? If so then you would need a modbus slave node in node red. I am not aware of a modbus slave node.


#5

I believe you are completely correct, and since there is not a slave node, I may be out of luck.

Thank you