General opinions on MQTT vs Modbus TCP


I am looking for a general opinion in terms of the application and reliability of two similar technologies, assume you have a Groov Epic Controlling a process, and you need to request some remote data from a local network. the remote device can be configured as modbus TCP slave, or run a small MQTT broker, from where the epic can read the data, being that both technologies can provide the same result, which one would you prefer?

Modbus TCP would potentially run “natively” on PACsoft, where MQTT would need the client running on nodered, using the internal API to pass the values to PACsoft, in addition to the fact that the remote device needs to be running the broker software as well with a similar arrangement.
On the other hand, MQTT can be configured with a password and specific addresses, where MB-TCP would be open to any queries.
We would have to dig deeper in terms of network resources, assuming both refresh at the same rate.

If this was a public network, there would be no question about the winner, but in a local network scenario, what are your thoughts?


With what you have given on a reliable local network with one address to one device, no requirement for encryption, Modbus all the way. Keep it simple.