ESP32 Modbus Communication Issue: Temperature Data Consistently Reads Zero Despite Successful Transactions (IDFGH-12723)

herryliq commented 2 months ago

Issue Summary:

I am experiencing an issue with reading temperature data via Modbus using an ESP32 microcontroller. The temperature values are consistently reported as zero, despite successful communications without any error codes.

Detailed Description:

Communication Status:

The communication with the Modbus slave device is successful, as indicated by the ESP_OK status. This suggests that the Modbus communication itself is functioning correctly.

Temperature Reading:

The retrieved temperature value is always 0.000000. This is problematic as it does not reflect the expected real-world temperature readings, which should be in Celsius.

Log Insights:

The operation is logged as successful with no errors (error: 0).
A characteristic type (3) is mentioned, though its specific meaning needs clarification based on the application documentation or source code.
The raw hexadecimal data received from the device is 0x312. This data does not seem to align correctly with expected temperature values.

Potential Issue Areas:

Data Parsing: There might be an issue with how the raw data (0x312) is being interpreted or converted into a usable temperature format.
Data Mapping: The configuration for how data is mapped from the Modbus registers to application-specific data structures may be incorrect or not aligned properly.

the log as follows:

D (9422) MB_PORT_COMMON: eMBMasterRTUReceive: Port exit critical␛[0m D (9422) MB_PORT_COMMON: 8666597: Packet data received successfully (0).␛[0m D (9432) POLL receive buffer: 04 02 01 36 ␛[0m D (9432) MB_PORT_COMMON: 8666597:EV_MASTER_FRAME_SENT␛[0m D (9442) POLL sent buffer: 04 00 00 00 01 ␛[0m D (9442) MB_PORT_COMMON: 8666597:EV_MASTER_EXECUTE␛[0m D (9452) MB_PORT_COMMON: 8666597:set event EV_ERROR_OK␛[0m D (9452) MB_PORT_COMMON: 8666597:EV_MASTER_ERROR_PROCESS␛[0m D (9462) MB_PORT_COMMON: vMBMasterCBRequestSuccess: Callback request success.␛[0m D (9472) MB_PORT_COMMON: Transaction (8666597), processing time(us) = 136362␛[0m D (9472) MB_PORT_COMMON: eMBMasterWaitRequestFinish: returned event = 0x80␛[0m D (9482) MB_CONTROLLER_MASTER: mbc_serial_master_get_parameter: Good response for get cid(0) = ESP_OK␛[0m ␛[0;32mI (9492) MASTER_TEST: Characteristic #0 Temperature (Celsius) value = (0x0) read successful.␛[0m ␛[0;32mI (10002) MASTER_TEST: mbc_master_get_cid_info: (param_key:1061160556), (mb_slave_addr:1)␛[0m D (10002) MB_PORT_COMMON: xMBMasterRunResTake:Take MB resource (500 ticks).␛[0m D (10002) MB_PORT_COMMON: xMBMasterRunResTake:Take MB resource (500 ticks).␛[0m D (10012) MB_PORT_COMMON: 9356874:EV_MASTER_FRAME_TRANSMIT␛[0m D (10012) POLL transmit buffer: 04 00 00 00 01 ␛[0m D (10022) MB_PORT_COMMON: eMBMasterRTUSend: Port enter critical.␛[0m D (10022) MB_PORT_COMMON: eMBMasterRTUSend: Port exit critical␛[0m D (10032) MB_PORT_COMMON: xMBMasterPortSerialSendRequest default␛[0m D (10042) MB_PORT_COMMON: vMBMasterPortTimersRespondTimeoutEnable Respond enable timeout.␛[0m D (10042) MB_MASTER_SERIAL: MB_TX_buffer sent: (9) bytes.␛[0m D (10052) MB_PORT_COMMON: xMBPortSerialWaitEvent, UART event: 1 ␛[0m D (10052) MB_MASTER_SERIAL: MB_uart[2] event:␛[0m D (10062) MB_MASTER_SERIAL: uart rx break.␛[0m D (10062) MB_PORT_COMMON: xMBPortSerialWaitEvent, UART event: 0 ␛[0m D (10072) MB_MASTER_SERIAL: MB_uart[2] event:␛[0m D (10072) MB_MASTER_SERIAL: Data event, len: 7.␛[0m D (10082) MB_MASTER_SERIAL: Received data: 8(bytes in buffer)␛[0m D (10082) MB_MASTER_SERIAL: Timeout occured, processed: 8 bytes␛[0m D (10092) MB_PORT_COMMON: 9356874:EV_MASTER_FRAME_RECEIVED␛[0m D (10102) MB_PORT_COMMON: xMBMasterPortSerialGetResponse default␛[0m D (10102) MB_PORT_COMMON: eMBMasterRTUReceive: Port enter critical.␛[0m D (10112) MB_PORT_COMMON: eMBMasterRTUReceive: Port exit critical␛[0m D (10112) MB_PORT_COMMON: 9356874: Packet data received successfully (0).␛[0m D (10122) POLL receive buffer: 04 02 01 36 ␛[0m D (10132) MB_PORT_COMMON: 9356874:EV_MASTER_FRAME_SENT␛[0m D (10132) POLL sent buffer: 04 00 00 00 01 ␛[0m D (10142) MB_PORT_COMMON: 9356874:EV_MASTER_EXECUTE␛[0m D (10142) MB_PORT_COMMON: 9356874:set event EV_ERROR_OK␛[0m D (10152) MB_PORT_COMMON: 9356874:EV_MASTER_ERROR_PROCESS␛[0m D (10152) MB_PORT_COMMON: vMBMasterCBRequestSuccess: Callback request success.␛[0m D (10162) MB_PORT_COMMON: Transaction (9356874), processing time(us) = 138536␛[0m D (10172) MB_PORT_COMMON: eMBMasterWaitRequestFinish: returned event = 0x80␛[0m D (10172) MB_CONTROLLER_MASTER: mbc_serial_master_get_parameter: Good response for get cid(0) = ESP_OK␛[0m ␛[0;32mI (10182) MASTER_TEST: Characteristic #0 Temperature (Celsius) value = (0x0) read successful.␛[0m

the source code was base from sample mb-master

The follows is my device_parameters define. {CID_INP_DATA_0,STR("Temperature"),STR("Celsius"),1,MB_PARAM_INPUT,0x0000,1,INPUT_OFFSET(input_data0),PARAM_TYPE_FLOAT,PARAM_SIZE_FLOAT,OPTS(-40,80,0.1),PAR_PERMS_READ},

` static void master_operation_func(void arg) { esp_err_t err = ESP_OK; float value = 0; uint8_t temp_data[4]={0}; bool alarm_state = false; const mb_parameter_descriptor_t param_descriptor = NULL;

ESP_LOGI(TAG, "Start modbus test...");

for(uint16_t retry = 0; retry <= MASTER_MAX_RETRY && (!alarm_state); retry++) {
    // Read all found characteristics from slave(s)
    for (uint16_t cid = 0; (err != ESP_ERR_NOT_FOUND) && cid < MASTER_MAX_CIDS; cid++)
    {
        // Get data from parameters description table
        // and use this information to fill the characteristics description table
        // and having all required fields in just one table
        err = mbc_master_get_cid_info(cid, &param_descriptor);
        ESP_LOGI(TAG, "mbc_master_get_cid_info: (param_key:%d), (mb_slave_addr:%d)", param_descriptor->param_key, param_descriptor->mb_slave_addr);

        if ((err != ESP_ERR_NOT_FOUND) && (param_descriptor != NULL)) {
            void* temp_data_ptr = master_get_param_data(param_descriptor);
            assert(temp_data_ptr);
            uint8_t type = 0;
            {
                err = mbc_master_get_parameter(cid, (char*)param_descriptor->param_key,
                                                    (uint8_t*)&value, &type);                                              
                if (err == ESP_OK) {
                    ESP_LOGI(TAG, "Characteristic #%d %s (%s) value = (0x%" PRIx32 ") read successful.",
                                    param_descriptor->cid,
                                    (char*)param_descriptor->param_key,
                                    (char*)param_descriptor->param_units,
                                    *(uint32_t*)temp_data); 
                } else {
                    ESP_LOGE(TAG, "Characteristic #%d (%s) read fail, err = 0x%x (%s).",
                                        param_descriptor->cid,
                                        (char*)param_descriptor->param_key,
                                        (int)err,
                                        (char*)esp_err_to_name(err));
                }
            }
            vTaskDelay(POLL_TIMEOUT_TICS); // timeout between polls
        }
    }
    vTaskDelay(UPDATE_CIDS_TIMEOUT_TICS); //
}

if (alarm_state) {
    ESP_LOGI(TAG, "Alarm triggered by cid #%d.",
                                    param_descriptor->cid);
} else {
    ESP_LOGE(TAG, "Alarm is not triggered after %d retries.",
                                    MASTER_MAX_RETRY);
}
ESP_LOGI(TAG, "Destroy master...");
ESP_ERROR_CHECK(mbc_master_destroy());

}

`

alisitsyn commented 2 months ago

@herryliq ,

The issue happens because your code above is incorrect.

Initialization of the temporary data pointer. This is where the data is designed to be stored.

void* temp_data_ptr = master_get_param_data(param_descriptor); // initializes the temp_data_ptr to the &input_reg_params.input_data0.

Get response from slave and returned data.

err = mbc_master_get_parameter(cid, (char*)param_descriptor->param_key,
                                                (uint8_t*)&value, &type);   // sends request and handle response, then saves the input data into data instance pointed by third parameter (&value)

Your modified code below prints the uint32_t value from the temp_data[] which is not initialized and is printed as 0x00000000.

ESP_LOGI(TAG, "Characteristic #%d %s (%s) value = (0x%" PRIx32 ") read successful.",
                                param_descriptor->cid,
                                (char*)param_descriptor->param_key,
                                (char*)param_descriptor->param_units,
                                *(uint32_t*)temp_data);

if you change the line above to below code, you will be able to get actual data received from slave.

ESP_LOGI(TAG, "Characteristic #%d %s (%s) value = (0x%" PRIx32 ") read successful.",
                                param_descriptor->cid,
                                (char*)param_descriptor->param_key,
                                (char*)param_descriptor->param_units,
                                *(uint32_t*)&value);

Please see the documentation pages the function mbc_master_get_parameter description

alisitsyn commented 2 months ago

The issue is duplicate with https://github.com/espressif/esp-idf/issues/13705

herryliq commented 2 months ago

The issue is duplicate with https://github.com/espressif/esp-idf/issues/13705

espressif / esp-modbus