Modbus TCP with ESPHome?

ESPHome
21

If your boiler has modbus rtu interface, you use rs485-ttl converter and esphome board. For tcp skip esphome.

1 Like
22

I have looked for sample ESPHome yaml for the KWB, but can’t find anything - I have copied the settings from other TCP modbus integrations but get no responses - my yaml is:


uart:
  id: modbus_uart
  tx_pin: GPIO16
  rx_pin: GPIO17
  baud_rate: 9600
  data_bits: 8
  parity: NONE
  stop_bits: 1

modbus:
  uart_id: modbus_uart
  id: modbus_client

modbus_controller:
  id: modbus_device
  modbus_id: modbus_client
  address: 0x1
  update_interval: 60s

sensor:
   - platform: modbus_controller
     modbus_controller_id: modbus_device
     name: Operating Hours
  #   # Betriebsstunden
  #   # 0x982
     address: 2337
     unit_of_measurement: "h"
     state_class: measurement
     value_type: U_WORD
     register_type: read

I get a log message of no repsonse. As I have added the RS485TTL via a cable onto the 2nd modbus connector on the board (and a 121ohm resistor). I don’t know if I need to register this with the KWB system as an extra peripheral, or whether I just need a different controller address?

23

Since your problem is not related to original post, I suggest you to open your own topic and post detailed description of your hardware (like rs485 converter) and your wiring. Also KWB model and modbus protocol sheet if you have.

24

Does this help?

25

Warning, most of MODBUS systems won’t answer if you don’t send a properly formatted message and that interrogates on a proper Modbus address so can be quite difficult to debug at begin…