I am using my ESP32 as a master that communicates to other devices that include SunGold/Mean Well solar inverters and a MeanWell DRS - https://www.meanwell.com/Upload/PDF/DRS-240,480.pdf.
With all of these devices I am able to successfuy program the ESP32 to be a master that sends an individual read/write with one parameter such as:
- const mb_parameter_descriptor_t device_parameters[] = {
- // { CID, Param Name, Units, Modbus Slave Addr, Modbus Reg Type, Reg Start, Reg Size, Instance Offset, Data Type, Data Size, Parameter Options, Access Mode}
- { CID_INP_DATA_0, STR("Data_channel_0"), STR("..."), MB_DEVICE_ADDR1, MB_PARAM_HOLDING, 0x00, 1,
- HOLD_OFFSET(holding_data0), PARAM_TYPE_U16, 2, OPTS( 0, 0xFFFF, 1 ), PAR_PERMS_READ_WRITE_TRIGGER }
- };
However, as soon as I program the ESP32 to read/write multiple parameters, such as:
- const mb_parameter_descriptor_t device_parameters[] = {
- // { CID, Param Name, Units, Modbus Slave Addr, Modbus Reg Type, Reg Start, Reg Size, Instance Offset, Data Type, Data Size, Parameter Options, Access Mode}
- { CID_INP_DATA_0, STR("Data_channel_0"), STR("..."), MB_DEVICE_ADDR1, MB_PARAM_HOLDING, 0x00, 1,
- HOLD_OFFSET(holding_data0), PARAM_TYPE_U16, 2, OPTS( 0, 0xFFFF, 1 ), PAR_PERMS_READ_WRITE_TRIGGER },
- { CID_HOLD_DATA_0, STR("Data_channel_0"), STR("..."), MB_DEVICE_ADDR1, MB_PARAM_HOLDING, 0x20, 1,
- HOLD_OFFSET(holding_data0), PARAM_TYPE_U16, 2, OPTS( 0, 0xFFFF, 1 ), PAR_PERMS_READ_WRITE_TRIGGER }
- };
- W (252) spi_flash: Detected size(8192k) larger than the size in the binary image header(2048k). Using the size in the binary image header.
- I (265) sleep: Configure to isolate all GPIO pins in sleep state
- I (272) sleep: Enable automatic switching of GPIO sleep configuration
- I (279) coexist: coex firmware version: 66616e60c
- I (284) coexist: coexist rom version 5b8dcfa
- I (290) main_task: Started on CPU0
- I (290) main_task: Calling app_main()
- I (290) uart: queue free spaces: 20
- I (350) MASTER_TEST: Modbus master stack initialized...
- I (450) MASTER_TEST: Start modbus test...
- I (450) MASTER_TEST: Characteristic #0 Data_channel_0 (...) value = 0.000000 (0x1) read successful.
- E (450) MB_CONTROLLER_MASTER: mbc_serial_master_get_parameter: The requested cid(1) is not configured correctly. Check data dictionary for correctness.
- E (460) MB_CONTROLLER_MASTER: mbc_master_get_parameter(74): Master get parameter failure, error=(0x102) (ESP_ERR_INVALID_ARG).
- E (480) MASTER_TEST: Characteristic #1 (Data_channel_0) read fail, err = 0x102 (ESP_ERR_INVALID_ARG).
- I (990) MASTER_TEST: Characteristic #0 Data_channel_0 (...) value = 0.000000 (0x1) read successful.
- E (990) MB_CONTROLLER_MASTER: mbc_serial_master_get_parameter: The requested cid(1) is not configured correctly. Check data dictionary for correctness.
- E (1000) MB_CONTROLLER_MASTER: mbc_master_get_parameter(74): Master get parameter failure, error=(0x102) (ESP_ERR_INVALID_ARG).
- E (1010) MASTER_TEST: Characteristic #1 (Data_channel_0) read fail, err = 0x102 (ESP_ERR_INVALID_ARG).
- I (1530) MASTER_TEST: Characteristic #0 Data_channel_0 (...) value = 0.000000 (0x1) read successful.
- E (1530) MB_CONTROLLER_MASTER: mbc_serial_master_get_parameter: The requested cid(1) is not configured correctly. Check data dictionary for correctness.
- E (1540) MB_CONTROLLER_MASTER: mbc_master_get_parameter(74): Master get parameter failure, error=(0x102) (ESP_ERR_INVALID_ARG).
- E (1560) MASTER_TEST: Characteristic #1 (Data_channel_0) read fail, err = 0x102 (ESP_ERR_INVALID_ARG).
- I (2070) MASTER_TEST: Characteristic #0 Data_channel_0 (...) value = 0.000000 (0x1) read successful.
- E (2070) MB_CONTROLLER_MASTER: mbc_serial_master_get_parameter: The requested cid(1) is not configured correctly. Check data dictionary for correctness.
- E (2080) MB_CONTROLLER_MASTER: mbc_master_get_parameter(74): Master get parameter failure, error=(0x102) (ESP_ERR_INVALID_ARG).
- E (2100) MASTER_TEST: Characteristic #1 (Data_channel_0) read fail, err = 0x102 (ESP_ERR_INVALID_ARG).
- /*
- * SPDX-FileCopyrightText: 2016-2023 Espressif Systems (Shanghai) CO LTD
- *
- * SPDX-License-Identifier: Apache-2.0
- */
- #include "string.h"
- #include "esp_log.h"
- #include "modbus_params.h" // for modbus parameters structures
- #include "mbcontroller.h"
- #include "sdkconfig.h"
- #define MB_PORT_NUM (CONFIG_MB_UART_PORT_NUM) // Number of UART port used for Modbus connection
- #define MB_DEV_SPEED (CONFIG_MB_UART_BAUD_RATE) // The communication speed of the UART
- // Note: Some pins on target chip cannot be assigned for UART communication.
- // See UART documentation for selected board and target to configure pins using Kconfig.
- // The number of parameters that intended to be used in the particular control process
- #define MASTER_MAX_CIDS num_device_parameters
- // Number of reading of parameters from slave
- #define MASTER_MAX_RETRY 30
- // Timeout to update cid over Modbus
- #define UPDATE_CIDS_TIMEOUT_MS (500)
- #define UPDATE_CIDS_TIMEOUT_TICS (UPDATE_CIDS_TIMEOUT_MS / portTICK_PERIOD_MS)
- // Timeout between polls
- #define POLL_TIMEOUT_MS (1)
- #define POLL_TIMEOUT_TICS (POLL_TIMEOUT_MS / portTICK_PERIOD_MS)
- // The macro to get offset for parameter in the appropriate structure
- #define HOLD_OFFSET(field) ((uint16_t)(offsetof(holding_reg_params_t, field) + 1))
- #define INPUT_OFFSET(field) ((uint16_t)(offsetof(input_reg_params_t, field) + 1))
- #define COIL_OFFSET(field) ((uint16_t)(offsetof(coil_reg_params_t, field) + 1))
- // Discrete offset macro
- #define DISCR_OFFSET(field) ((uint16_t)(offsetof(discrete_reg_params_t, field) + 1))
- #define STR(fieldname) ((const char*)( fieldname ))
- // Options can be used as bit masks or parameter limits
- #define OPTS(min_val, max_val, step_val) { .opt1 = min_val, .opt2 = max_val, .opt3 = step_val }
- static const char *TAG = "MASTER_TEST";
- // Enumeration of modbus device addresses accessed by master device
- enum {
- MB_DEVICE_ADDR1 = 131 // Only one slave device used for the test (add other slave addresses here)
- };
- // Enumeration of all supported CIDs for device (used in parameter definition table)
- enum {
- CID_INP_DATA_0 = 0,
- CID_HOLD_DATA_0,
- CID_INP_DATA_1,
- CID_HOLD_DATA_1,
- CID_INP_DATA_2,
- CID_HOLD_DATA_2,
- CID_HOLD_TEST_REG,
- CID_RELAY_P1,
- CID_RELAY_P2,
- CID_DISCR_P1,
- CID_COUNT
- };
- // Example Data (Object) Dictionary for Modbus parameters:
- // The CID field in the table must be unique.
- // Modbus Slave Addr field defines slave address of the device with correspond parameter.
- // Modbus Reg Type - Type of Modbus register area (Holding register, Input Register and such).
- // Reg Start field defines the start Modbus register number and Reg Size defines the number of registers for the characteristic accordingly.
- // The Instance Offset defines offset in the appropriate parameter structure that will be used as instance to save parameter value.
- // Data Type, Data Size specify type of the characteristic and its data size.
- // Parameter Options field specifies the options that can be used to process parameter value (limits or masks).
- // Access Mode - can be used to implement custom options for processing of characteristic (Read/Write restrictions, factory mode values and etc).
- const mb_parameter_descriptor_t device_parameters[] = {
- // { CID, Param Name, Units, Modbus Slave Addr, Modbus Reg Type, Reg Start, Reg Size, Instance Offset, Data Type, Data Size, Parameter Options, Access Mode}
- { CID_INP_DATA_0, STR("Data_channel_0"), STR("..."), MB_DEVICE_ADDR1, MB_PARAM_HOLDING, 0x00, 1,
- HOLD_OFFSET(holding_data0), PARAM_TYPE_U16, 2, OPTS( 0, 0xFFFF, 1 ), PAR_PERMS_READ_WRITE_TRIGGER },
- { CID_HOLD_DATA_0, STR("Data_channel_0"), STR("..."), MB_DEVICE_ADDR1, MB_PARAM_HOLDING, 0x20, 1,
- HOLD_OFFSET(holding_data0), PARAM_TYPE_U16, 2, OPTS( 0, 0xFFFF, 1 ), PAR_PERMS_READ_WRITE_TRIGGER }
- };
- //// { CID, Param Name, Units, Modbus Slave Addr, Modbus Reg Type, Reg Start, Reg Size, Instance Offset, Data Type, Data Size, Parameter Options, Access Mode}
- //{ CID_INP_DATA_0, STR("Data_channel_0"), STR("..."), MB_DEVICE_ADDR1, MB_PARAM_HOLDING, 0x00, 1,
- // HOLD_OFFSET(holding_data0), PARAM_TYPE_U16, 2, OPTS( 0, 0xFFFF, 1 ), PAR_PERMS_READ_WRITE_TRIGGER },
- //{ CID_HOLD_DATA_0, STR("Data_channel_0"), STR("..."), MB_DEVICE_ADDR1, MB_PARAM_HOLDING, 0x20, 1,
- // HOLD_OFFSET(holding_data0), PARAM_TYPE_U16, 2, OPTS( 0, 0xFFFF, 1 ), PAR_PERMS_READ_WRITE_TRIGGER }
- // Calculate number of parameters in the table
- const uint16_t num_device_parameters = (sizeof(device_parameters)/sizeof(device_parameters[0]));
- // The function to get pointer to parameter storage (instance) according to parameter description table
- static void* master_get_param_data(const mb_parameter_descriptor_t* param_descriptor)
- {
- assert(param_descriptor != NULL);
- void* instance_ptr = NULL;
- if (param_descriptor->param_offset != 0) {
- switch(param_descriptor->mb_param_type)
- {
- case MB_PARAM_HOLDING:
- instance_ptr = ((void*)&holding_reg_params + param_descriptor->param_offset - 1);
- break;
- case MB_PARAM_INPUT:
- instance_ptr = ((void*)&input_reg_params + param_descriptor->param_offset - 1);
- break;
- case MB_PARAM_COIL:
- instance_ptr = ((void*)&coil_reg_params + param_descriptor->param_offset - 1);
- break;
- case MB_PARAM_DISCRETE:
- instance_ptr = ((void*)&discrete_reg_params + param_descriptor->param_offset - 1);
- break;
- default:
- instance_ptr = NULL;
- break;
- }
- } else {
- ESP_LOGE(TAG, "Wrong parameter offset for CID #%u", (unsigned)param_descriptor->cid);
- assert(instance_ptr != NULL);
- }
- return instance_ptr;
- }
- // User operation function to read slave values and check alarm
- static void master_operation_func(void *arg)
- {
- esp_err_t err = ESP_OK;
- float value = 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, ¶m_descriptor);
- 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;
- if ((param_descriptor->param_type == PARAM_TYPE_ASCII) &&
- (param_descriptor->cid == CID_HOLD_TEST_REG)) {
- // Check for long array of registers of type PARAM_TYPE_ASCII
- err = mbc_master_get_parameter(cid, (char*)param_descriptor->param_key,
- (uint8_t*)temp_data_ptr, &type);
- if (err == ESP_OK) {
- ESP_LOGI(TAG, "Characteristic #%u %s (%s) value = (0x%" PRIx32 ") read successful.",
- param_descriptor->cid,
- param_descriptor->param_key,
- param_descriptor->param_units,
- *(uint32_t*)temp_data_ptr);
- // Initialize data of test array and write to slave
- if (*(uint32_t*)temp_data_ptr != 0xAAAAAAAA) {
- memset((void*)temp_data_ptr, 0xAA, param_descriptor->param_size);
- *(uint32_t*)temp_data_ptr = 0xAAAAAAAA;
- err = mbc_master_set_parameter(cid, (char*)param_descriptor->param_key,
- (uint8_t*)temp_data_ptr, &type);
- if (err == ESP_OK) {
- ESP_LOGI(TAG, "Characteristic #%u %s (%s) value = (0x%" PRIx32 "), write successful.",
- param_descriptor->cid,
- param_descriptor->param_key,
- param_descriptor->param_units,
- *(uint32_t*)temp_data_ptr);
- } else {
- ESP_LOGE(TAG, "Characteristic #%u (%s) write fail, err = 0x%x (%s).",
- param_descriptor->cid,
- param_descriptor->param_key,
- (int)err,
- (char*)esp_err_to_name(err));
- }
- }
- } else {
- ESP_LOGE(TAG, "Characteristic #%u (%s) read fail, err = 0x%x (%s).",
- param_descriptor->cid,
- param_descriptor->param_key,
- (int)err,
- (char*)esp_err_to_name(err));
- }
- } else {
- err = mbc_master_get_parameter(cid, (char*)param_descriptor->param_key,
- (uint8_t*)temp_data_ptr, &type);
- if (err == ESP_OK) {
- if ((param_descriptor->mb_param_type == MB_PARAM_HOLDING) ||
- (param_descriptor->mb_param_type == MB_PARAM_INPUT)) {
- value = *(float*)temp_data_ptr;
- ESP_LOGI(TAG, "Characteristic #%u %s (%s) value = %f (0x%" PRIx32 ") read successful.",
- param_descriptor->cid,
- param_descriptor->param_key,
- param_descriptor->param_units,
- value,
- *(uint32_t*)temp_data_ptr);
- if (((value > param_descriptor->param_opts.max) ||
- (value < param_descriptor->param_opts.min))) {
- alarm_state = true;
- break;
- }
- } else {
- uint8_t state = *(uint8_t*)temp_data_ptr;
- const char* rw_str = (state & param_descriptor->param_opts.opt1) ? "ON" : "OFF";
- if ((state & param_descriptor->param_opts.opt2) == param_descriptor->param_opts.opt2) {
- ESP_LOGI(TAG, "Characteristic #%u %s (%s) value = %s (0x%" PRIx8 ") read successful.",
- param_descriptor->cid,
- param_descriptor->param_key,
- param_descriptor->param_units,
- (const char*)rw_str,
- *(uint8_t*)temp_data_ptr);
- } else {
- ESP_LOGE(TAG, "Characteristic #%u %s (%s) value = %s (0x%" PRIx8 "), unexpected value.",
- param_descriptor->cid,
- param_descriptor->param_key,
- param_descriptor->param_units,
- (const char*)rw_str,
- *(uint8_t*)temp_data_ptr);
- alarm_state = true;
- break;
- }
- if (state & param_descriptor->param_opts.opt1) {
- alarm_state = true;
- break;
- }
- }
- } else {
- ESP_LOGE(TAG, "Characteristic #%u (%s) read fail, err = 0x%x (%s).",
- param_descriptor->cid,
- 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 #%u.", param_descriptor->cid);
- } else {
- ESP_LOGE(TAG, "Alarm is not triggered after %u retries.", MASTER_MAX_RETRY);
- }
- ESP_LOGI(TAG, "Destroy master...");
- ESP_ERROR_CHECK(mbc_master_destroy());
- }
- // Modbus master initialization
- static esp_err_t master_init(void)
- {
- // Initialize and start Modbus controller
- mb_communication_info_t comm = {
- .port = MB_PORT_NUM,
- #if CONFIG_MB_COMM_MODE_ASCII
- .mode = MB_MODE_ASCII,
- #elif CONFIG_MB_COMM_MODE_RTU
- .mode = MB_MODE_RTU,
- #endif
- .baudrate = MB_DEV_SPEED,
- .parity = MB_PARITY_NONE
- };
- void* master_handler = NULL;
- esp_err_t err = mbc_master_init(MB_PORT_SERIAL_MASTER, &master_handler);
- MB_RETURN_ON_FALSE((master_handler != NULL), ESP_ERR_INVALID_STATE, TAG,
- "mb controller initialization fail.");
- MB_RETURN_ON_FALSE((err == ESP_OK), ESP_ERR_INVALID_STATE, TAG,
- "mb controller initialization fail, returns(0x%x).", (int)err);
- err = mbc_master_setup((void*)&comm);
- MB_RETURN_ON_FALSE((err == ESP_OK), ESP_ERR_INVALID_STATE, TAG,
- "mb controller setup fail, returns(0x%x).", (int)err);
- // Set UART pin numbers
- err = uart_set_pin(MB_PORT_NUM, CONFIG_MB_UART_TXD, CONFIG_MB_UART_RXD,
- CONFIG_MB_UART_RTS, UART_PIN_NO_CHANGE);
- MB_RETURN_ON_FALSE((err == ESP_OK), ESP_ERR_INVALID_STATE, TAG,
- "mb serial set pin failure, uart_set_pin() returned (0x%x).", (int)err);
- err = mbc_master_start();
- MB_RETURN_ON_FALSE((err == ESP_OK), ESP_ERR_INVALID_STATE, TAG,
- "mb controller start fail, returned (0x%x).", (int)err);
- // Set driver mode to Half Duplex
- err = uart_set_mode(MB_PORT_NUM, UART_MODE_RS485_HALF_DUPLEX);
- MB_RETURN_ON_FALSE((err == ESP_OK), ESP_ERR_INVALID_STATE, TAG,
- "mb serial set mode failure, uart_set_mode() returned (0x%x).", (int)err);
- vTaskDelay(5);
- err = mbc_master_set_descriptor(&device_parameters[0], num_device_parameters);
- MB_RETURN_ON_FALSE((err == ESP_OK), ESP_ERR_INVALID_STATE, TAG,
- "mb controller set descriptor fail, returns(0x%x).", (int)err);
- ESP_LOGI(TAG, "Modbus master stack initialized...");
- return err;
- }
- void app_main(void)
- {
- // Initialization of device peripheral and objects
- ESP_ERROR_CHECK(master_init());
- vTaskDelay(10);
- master_operation_func(NULL);
- }