Connecting Multiple Modbus Sensors to A16 (ESPHome)

[Gleb]

I'd like to greet all the forum members. I’m reaching out to ask for your help with an issue I’m experiencing.

I connected 7 sensors to an RS485 Modbus bus, but only 4 of them work simultaneously. When I connect each sensor individually, they all respond correctly. However, when I try to initialize more than 4 sensors in the YAML configuration (e.g., 1-2-3-4), they are displayed and work fine. But as soon as I add more sensors (e.g., 5-6-7), some of them stop responding or are not displayed at all.
I am using an A16 with ESPHome integrated into Home Assistant.


...
uart:
  - id: uart_modbus
    tx_pin: GPIO13
    rx_pin: GPIO16
    baud_rate: 4800
modbus:
  - uart_id: uart_modbus
    setup_priority: -10
    send_wait_time: 500 ms
    id: modbus1
modbus_controller:
  - id: modbus_sensor_2
    address: 0x02  
    modbus_id: modbus1
    update_interval: 5s
    offline_skip_updates: 2
    max_cmd_retries: 4
 
  - id: modbus_sensor_4
    address: 0x04  
    modbus_id: modbus1
    update_interval: 5s
    offline_skip_updates: 2
    max_cmd_retries: 4
  - id: modbus_sensor_7
    address: 0x07  
    modbus_id: modbus1
    update_interval: 5s
    offline_skip_updates: 2
    max_cmd_retries: 4
  - id: modbus_sensor_8
    address: 0x08  
    modbus_id: modbus1
    update_interval: 5s
    offline_skip_updates: 2
    max_cmd_retries: 4
...
...
sensor:
  - platform: modbus_controller
    modbus_controller_id: modbus_sensor_2
    name: "t_2"
    id: temperature_sensor_2
    address: 0x0001
    register_type: holding
    value_type: U_WORD
    force_new_range: true
    unit_of_measurement: "°C"
    accuracy_decimals: 2
    filters:
      - multiply: 0.1
  - platform: modbus_controller
    modbus_controller_id: modbus_sensor_2
    name: "h_2"
    id: humidity_sensor_2
    address: 0x0000
    register_type: holding
    value_type: U_WORD
    unit_of_measurement: "%"
    accuracy_decimals: 2
    filters:
      - multiply: 0.1
  - platform: modbus_controller
    modbus_controller_id: modbus_sensor_4
    name: "t_4"
    id: temperature_sensor_4
    address: 0x0001
    register_type: holding
    value_type: U_WORD
    force_new_range: true
    unit_of_measurement: "°C"
    accuracy_decimals: 2
    filters:
      - multiply: 0.1
  - platform: modbus_controller
    modbus_controller_id: modbus_sensor_4
    name: "h_4"
    id: humidity_sensor_4
    address: 0x0000
    register_type: holding
    value_type: U_WORD
    unit_of_measurement: "%"
    accuracy_decimals: 2
    filters:
      - multiply: 0.1
   
  - platform: modbus_controller
    modbus_controller_id: modbus_sensor_7
    name: "t_i"
    id: temperature_sensor_7
    address: 0x0001
    register_type: holding
    value_type: U_WORD
    force_new_range: true
    unit_of_measurement: "°C"
    accuracy_decimals: 2
    filters:
      - lambda: |-
          if (x > 32767) {
          return (x - 65536) / 10.0;
          } else {
          return x / 10.0;
          }
   
  - platform: modbus_controller
    modbus_controller_id: modbus_sensor_8
    name: "t_k"
    id: temperature_sensor_8
    address: 0x0001
    register_type: holding
    value_type: U_WORD
    force_new_range: true
    unit_of_measurement: "°C"
    accuracy_decimals: 2
    filters:
      - multiply: 0.1  
...

[admin]

which sensor you are using? Can you take a photo.

[Gleb]

Какой датчик вы используете? Можно сделать фото.

[admin]

i suggest you use a USB-RS485 adapter to test your sensor directly first step. if the sensor work well , then add to KC868-A16 board.

[Gleb]

Maybe you misunderstood me.
I've already changed the addresses on all the sensors. All the addresses are different. The sensors are connected individually or in groups of less than 5 without problems. But when I initialize MORE than 5 sensors in YAML, the panel also shows 5 sensors (and the added sensors are not polled, I don't see them in the logs). And any 5 sensors are displayed, in any combinations.

My system needs a minimum of 6 sensors to work.
In general, I can connect an additional RSMAX module for one more sensor, but it is strange, because the bus is designed for a huge number of devices.

[Gleb]

I apologize for the misinformation.
- It turns out that all sensors are displayed in the logs, but home assistant does not display them correctly. No more than 5 sensors.

[admin]

next month when have free time, i will test 6pcs of RS485 temperature sensors with one bus in home assistant, then feedback to you.

[Gleb]

next month when have free time, i will test 6pcs of RS485 temperature sensors with one bus in home assistant, then feedback to you.

Thank you!

[Gleb]

Moreover, I noticed that in the hass panel, while connecting more than 4 sensors, some sensors display their correct value or the one that was lost.

[admin]

can you reduce the baud rate of sensor?