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dumpfheimer / olimpia_splendid_bi2_modbus_controller

Modbus Controller for Olimpia Splendid BI2 fancoils and similar devices.
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Modbus errors in communication #3

Open djreturn opened 10 months ago

djreturn commented 10 months ago

Hello,

First I want to say thank you for this project! I started to build my self based on modbus tcp/rtu over wifi and raspberry pi, but this project have nice features like MQTT, OTA update, keep alive communication and etc.

I manage few fan coils, each of them have MINI D1 CH340 USB-C and MAX485. All settings are sended and readed over http. From time to time values which is returned from the fan coil is not accurate. Also modbusErrorRatio is about 53% errors Modbus cables are very short and MAX485 is soldered directly over MINI D1

Can you give me suggestions what I can look/debug?

dumpfheimer commented 10 months ago

Hi!

This sounds like more of a problem with your physical Modbus Connection than with the project itself.

What do you mean wit inaccurate vales in responses?

I am no professional and outside of the scope of this project I have no experience with Modbus.

Anyway, what comes to mind is:

  1. Terminating resistor at the end of the line (mostly for long lines)
  2. Topology of the network (are they all in line? Only if multiple fancoils on one controller)
  3. Are all fan coils using different addresses? (Or they might be answering at the same time; only if multiple fancoils on one controller)
  4. Common ground (consider powering the controller off of a fancoils 5V

If I understood correctly you are using one controller per fancoil. If this is the case first check number 4, power to the controller and consider powering it off of the 5V on board. There should be unused pins on your fancoil controller board

Hope you find your issue, feel free to ask for more help here and please do post your solution - if found.

Good luck!

r0bb10 commented 7 months ago

Hello,

First I want to say thank you for this project! I started to build my self based on modbus tcp/rtu over wifi and raspberry pi, but this project have nice features like MQTT, OTA update, keep alive communication and etc.

I manage few fan coils, each of them have MINI D1 CH340 USB-C and MAX485. All settings are sended and readed over http. From time to time values which is returned from the fan coil is not accurate. Also modbusErrorRatio is about 53% errors Modbus cables are very short and MAX485 is soldered directly over MINI D1

Can you give me suggestions what I can look/debug?

the problem is probably the GND of the Wemos and the GND of the fancoil board, you should have exposed some serial headers with gnd and 5v, check that i had the same issue and fixed this way.