Modbus RTU Gateway development

Theengs OpenMQTTGateway
1

Hi,

First of all - thank you for such a great project :slight_smile: !

Currently, I’m looking for the best way to deploy a MQTT ↔ MODBUS RTU gateway. I found OpenMQTTGateway and thought it sounds perfect - but to modbus support yet.

Instead of hard coding for a single project, I would rather develop and contribute to a project like OMG since most of the components such as MQTT and browser UI are already integrated.

However, there are some prerequisites I have on my current project and I wonder if they can be met by OMG. I assume yes, but want to rather ask now before getting deeper into the project:

  • ESP32 support (obviously yes)
  • wired ethernet support
  • very fast MQTT ↔ MODBUS transition once the gateway exists (milliseconds)

Can those requirements be met?

And as the final question: Is there interest at all in extending OMG to protocols like modbus or is that a direction which is out of focus of the project?

edit: clarify Mobus RTU

2

hello,

Thanks for considering OMG for your project, a MODBUStoMQTT gateway is interesting and could be added to the project. TO answer to your questions:

  • ESP32 support (obviously yes) → I confirm
  • wired ethernet support → yes already supported with some boards like the Olimex ones
  • very fast MQTT ↔ MODBUS transition once the gateway exists (milliseconds)
    What do you mean by “Once the gateway exists” ?
3

wired ethernet support → yes already supported with some boards like the Olimex ones

so I guess it’s a matter of wether the phy is supported by the ESP?

very fast MQTT ↔ MODBUS transition once the gateway exists (milliseconds)
What do you mean by “Once the gateway exists” ?

once the software is written - I’m sorry that sounded strange :upside_down_face:

The reason for asking this question is wether there are any known limiting factors on latency within OMG - without reviewing the code. Of course not counting serial IO / modbus latency.

Also, speed (latency) and reliability are the reasons for choosing wired ethernet over wifi.

4

Yes indeed and having a proper driver for the ethernet component

I would propose testing it, as we never had such requirements for “milliseconds”

5

All right.

I will try to dig into it once I get the hardware. I ordered some small chinese parts which have an ESP32, ethernet (100Mbit RJ45) and RS-485 build right on it.

I’m quite excited - thank you :slight_smile:

1 Like
6

There is any work in “MODBUStoMQTT” ?