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02 illegal Data Address from Modbus Slave Example

Posted: Wed Jan 25, 2023 3:54 am
by chikichaka
I'm testing Modubs RTU example.
Whenever I tried to read Input Register value.
I can see 02 Illegal Data Address.

I'm using Modbus Poll window program to check Modbus communication.
other functions are working well such as Coils, Discrete Input, Holding Registers.

I use code from example here:

https://github.com/espressif/esp-idf/bl ... in/slave.c

Re: 02 illegal Data Address from Modbus Slave Example

Posted: Fri Jan 27, 2023 12:26 pm
by ESP_alisitsyn
@chikichaka ,

The slave configures two register areas for input registers:

Reg input area 1: 0, length: 8
Reg input area 2: 158, length: 8
Screenshot at 2023-01-27 13-31-03.png
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Screenshot at 2023-01-27 13-18-33.png
Screenshot at 2023-01-27 13-18-33.png (44.97 KiB) Viewed 3148 times


If you configure Modbus poll to read these registers you will get the data correctly.
Screenshot at 2023-01-27 13-26-29.png
Screenshot at 2023-01-27 13-26-29.png (49.52 KiB) Viewed 3155 times