Hello @prokampas, Why you are using mbc_master_send_request(&req, &data); function of modbus controller instead of mbc_tcp_master_set_parameter(), mbc_tcp_master_get_parameter() ? I can expect several reasons for the failures: 1. Incorrect initialisation of master and state machine. 2. The device do...

Hi JuhToiva,

Thanks for the update. Let me know if you have any issues.

Hi @adam_esp,

The previous answer from @fahad_ali_sarwar is correct. The Modbus TCP master/slave functionality implemented from ESP-IDF v4.2.
https://docs.espressif.com/projects/esp ... ght=modbus

Hi davdav, since modbus request will be made "on-the-fly" (no knowledge of what function code and/or register number is requested), is it possible to avoid the setup of the "parameter descriptor" as reported in the example: is is possible to use only "mbc_master_send_request" API to read/write the m...

Hi @xyashpatilx, I need more information about your master data dictionary and slave register descriptors to identify the issue. The existing serial master and slave examples work just fine with default configuration and stress tested. For now i can propose to increase CONFIG_FMB_MASTER_TIMEOUT_MS_R...

Hello @sabin.john, The additional option in `mb_communication_info_t` can be implemented. The reason why it was not implemented is compatibility with original freemodbus code which does not provide a way to explicitly select number of stop bits (See the BOOL xMBPortSerialInit(Char ucPORT, ULONG ulBa...

Hi @JuhToiva, Modbus uses the timer group to measure the required timeouts which can be configured using kconfig options (CONFIG_FMB_TIMER_GROUP, CONFIG_FMB_TIMER_INDEX). The Error code 0x105 is ESP_ERR_NOT_FOUND (for your reference: https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-re...

@ jas39_,

This has been already fixed in my MR. Thanks for finding.

Hello,

The modbus controller layer is above Modbus. This logic with parameter name was used as additional check to avoid or detect possible data dictionary misconfiguration issues from user side.

It is pretty simple to implement in current update but let me know if you need help. Please make sure your callback function can safely return after maximum timeout even when r/w operation is not completed.