Modbus Master Crashes: assert failed: xMBMasterRTUReceiveFSM mbrtu_m.c:235

[Michael.Uray]

I am run after some time of operation into the problem, that my ESP32 restarts with the above mentioned error.
The Modbus master code is pretty much the same as the example which is included in the ESP IDF, i just changed a few minor things.

Code: [Select all] [Expand/Collapse]

1. I (1911922) count_task: RAM left 123264; mb_master_hwm: 1508, count_task_hwm: 20, mqtt_ssl_main_hwm: 6276
2. I (1912262) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
3. I (1912762) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
4. I (1913262) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
5. I (1913762) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
6. I (1914262) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
7. I (1914762) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
8. I (1914922) count_task: RAM left 123640; mb_master_hwm: 1508, count_task_hwm: 20, mqtt_ssl_main_hwm: 6276
9. I (1915262) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
10. I (1915762) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
11. I (1916262) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
12. I (1916762) MASTER_TEST: Characteristic #0 Data_channel_0 (kW) value = 4531.000000 (0x458d9800) read successful. Restarted: 0
13.  
14. assert failed: xMBMasterRTUReceiveFSM mbrtu_m.c:235 (( eSndState == STATE_M_TX_IDLE ) || ( eSndState == STATE_M_TX_XFWR ))
15.  
16.  
17. Backtrace:0x40081c02:0x3ffd00700x40089559:0x3ffd0090 0x400909b5:0x3ffd00b0 0x400e0751:0x3ffd01d0 0x400e1545:0x3ffd0200 0x400e15b4:0x3ffd0230 0x4008cdad:0x3ffd0260
18. 0x40081c02: panic_abort at C:/Users/Michael.Uray/esp/esp-idf/components/esp_system/panic.c:402
19.  
20. 0x40089559: esp_system_abort at C:/Users/Michael.Uray/esp/esp-idf/components/esp_system/esp_system.c:128
21.  
22. 0x400909b5: __assert_func at C:/Users/Michael.Uray/esp/esp-idf/components/newlib/assert.c:85
23.  
24. 0x400e0751: xMBMasterRTUReceiveFSM at C:/Users/Michael.Uray/esp/esp-idf/components/freemodbus/modbus/rtu/mbrtu_m.c:235 (discriminator 2)
25.  
26. 0x400e1545: usMBMasterPortSerialRxPoll at C:/Users/Michael.Uray/esp/esp-idf/components/freemodbus/port/portserial_m.c:94
27.  
28. 0x400e15b4: vUartTask at C:/Users/Michael.Uray/esp/esp-idf/components/freemodbus/port/portserial_m.c:142
29.  
30. 0x4008cdad: vPortTaskWrapper at C:/Users/Michael.Uray/esp/esp-idf/components/freertos/port/xtensa/port.c:131
31.  
32.  
33.  
34.  
35.  
36. ELF file SHA256: 375376b08aba9e70
37.  
38. Rebooting...
39. ets Jul 29 2019 12:21:46

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My application runs a few tasks in parallel if that matters, which is a websocket/webserver, modbus client, modbus server and mqtt.

Code: [Select all] [Expand/Collapse]

1. void app_main()
2. {
3.   const static char *TAG = "main";
4.  
5.   esp_err_t err = nvs_flash_init();
6.   if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND)
7.   {
8.     // NVS partition was truncated and needs to be erased
9.     // Retry nvs_flash_init
10.     ESP_ERROR_CHECK(nvs_flash_erase());
11.     err = nvs_flash_init();
12.   }
13.   ESP_ERROR_CHECK(err);
14.  
15.   wifi_app_main();
16.  
17.   led_setup();
18.   ws_server_start();
19.  
20.   xTaskCreate(&nvs_main, "nvs_main", 2000, NULL, 9, NULL);
21.   xTaskCreate(&server_task, "server_task", 2000, NULL, 9, NULL);
22.   xTaskCreate(&server_handle_task, "server_handle_task", 4000, NULL, 6, NULL);
23.   xTaskCreate(&count_task, "count_task", 2000, NULL, 2, NULL);
24.   xTaskCreate(&mb_master_main, "mb_master_main", 3500, NULL, 9, &mb_master_main_th);
25.   xTaskCreate(&mb_slave_main, "mb_slave_main", 3500, NULL, 9, NULL);
26.   xTaskCreate(&mqtt_ssl_main, "mqtt_ssl_main", 1024 * 8, NULL, 9, &mqtt_ssl_main_th);
27. }

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What could cause this issue and how to trace it back?
(I am a beginner with ESP IDF)

[ESP_alisitsyn]

Hello Michael.Uray,

As I understand you use the freemodbus component from esp-idf v4.4. Unfortunately this component will not work with the configuration used in your application because your other tasks blocks the normal processing of modbus tasks.

Please try to fix this using the instruction below:
1. Create the components folder in the root folder of your application.
2. Copy the component folder "espressif__esp-modbus" from the project here https://github.com/alisitsyn/modbus_su ... components to your "components" folder.
3. Add the line to your root CMakeLists.txt file: https://github.com/alisitsyn/modbus_sup ... sts.txt#L6.
4. Change the other tasks priority of `9` to `8`.
4. `idf.py fullclean` or delete the build folder of your application manually then rebuild the project.
5. Rerun your project.

Please also take a look to the migration guide notes for modbus:
https://github.com/espressif/esp-idf/bl ... esp-modbus

If you still have issues with the update please send the log here. In this case it may require retries also to work in your configuration.
Thank you.

[Michael.Uray]

Thanks for your response.
I found in the meanwhile out, that a too low stack on another task caused the problem, even the highWatermark did not report a too low stack.
Please see also this forum entry:
https://forums.freertos.org/t/assert-fa ... -idf/16127