RTU OVER TCP Unable to decode response

ESPHome
1

HA modbus RTU OVER TCP connect ESP_easy ser2net, can’t recieve full data bytes, NO CRC BYTES. As the modbus protcol ,the recieve datas should be 9,but in fact only 7

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image1170×272 68.4 KB

My configration code is below.

modbus:
  - name: "SMA"
    type: rtuovertcp
    host: 192.168.0.124
    port: 502
    delay: 5
    timeout: 5
    sensors:
      - name: IM1281B
        unit_of_measurement: ℃
        slave: 2
        address: 0078
        count: 1
        data_type: uint
        scale: 0.01
        precision: 2
        scan_interval: 30
logger:
  logs:
    homeassistant.components.modbus: debug
    pymodbus.client: debug
2

Post your log , not a pic of it.

3 
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.client.sync] Connection to Modbus server established. Socket ('192.168.0.13', 58373)
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.transaction] Current transaction state - TRANSACTION_COMPLETE
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.transaction] Running transaction 2
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.transaction] Clearing current Frame : - 0x2 0x3 0x4 0x0 0x0 0xa 0xbe
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.framer.rtu_framer] Resetting frame - Current Frame in buffer - 0x2 0x3 0x4 0x0 0x0 0xa 0xbe
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.transaction] SEND: 0x2 0x3 0x0 0x4e 0x0 0x1 0xe4 0x2e
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.framer.rtu_framer] Changing state to IDLE - Last Frame End - 1625314390.859892, Current Time stamp - 1625314420.829982
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.client.sync] New Transaction state 'SENDING'
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.transaction] Changing transaction state from 'SENDING' to 'WAITING FOR REPLY'
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.transaction] Changing transaction state from 'WAITING FOR REPLY' to 'PROCESSING REPLY'
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.transaction] RECV: 0x2 0x3 0x4 0x0 0x0 0xa 0xbe
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.framer.rtu_framer] Frame - [b'\x02\x03\x04\x00\x00\n\xbe'] not ready
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.transaction] Getting transaction 2
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [pymodbus.transaction] Changing transaction state from 'PROCESSING REPLY' to 'TRANSACTION_COMPLETE'
2021-07-03 20:13:40 DEBUG (SyncWorker_3) [homeassistant.components.modbus.modbus] Pymodbus: Modbus Error: [Input/Output] No Response received from the remote unit/Unable to decode response

when i use the modbusscan tool to test the device, the datas are full and correct ,but the modbusscan tool “Valid Slave Responses” is 0.

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4

when i use the modbusPoll tool to test the device, the datas are full and correct ,but the modbusPoll tool shows “Checksum error”.

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image881×588 20.9 KB

5

I found the reason . My power meter(IM1281B) is not a standard modbus protocol device. In it’s protocol, a register has 4 bytes datas, but standard modbus protocol only has 2 bytes datas in a register.
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