02 illegal Data Address from Modbus Slave Example

chikichaka
Posts: 6
Joined: Tue Aug 09, 2022 7:53 am

02 illegal Data Address from Modbus Slave Example

Postby chikichaka » Wed Jan 25, 2023 3:54 am

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

ESP_alisitsyn
Posts: 185
Joined: Fri Feb 01, 2019 4:02 pm
Contact:

Re: 02 illegal Data Address from Modbus Slave Example

Postby ESP_alisitsyn » Fri Jan 27, 2023 12:26 pm

@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
Screenshot at 2023-01-27 13-31-03.png (43.77 KiB) Viewed 46 times
Screenshot at 2023-01-27 13-18-33.png
Screenshot at 2023-01-27 13-18-33.png (44.97 KiB) Viewed 42 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 49 times

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