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Question about ESP32 modbus slave example

Posted: Thu May 02, 2019 6:34 am
by jackyc58
Has anyone used the ESP32 modbus feature?

I use the latest (git at 2019/04/30) ESP-IDF and the accompanying example modbus_slave, I tested it to get the following result:

Modbus Master send: 01 01 00 00 00 04 3D C9
Modbus_slave replies to two results:
01 01 01 05 91 8B (The first reply after booting)
40 40 40 41 64 F1 (Reply after the second time)

Q1. “40 40 40 41 64 F1” Is this correct? If so, how do you interpret the content?
Q2. If it is the format of the first reply (01 01 01 05 91 8B), how to set it in the program?

Thanks!

Re: Question about ESP32 modbus slave example

Posted: Tue May 07, 2019 7:42 am
by ESP_alisitsyn
Hi jackyc58,

I would like to make a link here to our discussion on GitHub with the answers: https://github.com/espressif/esp-idf/issues/3431
Please let me know if you have any other questions.

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Alex