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MODBUS response error

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bikashh

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hello friends,
I am working in a modbus project...as i am new to this i am not able to figure out the exact problem...

My hardware which is a master is sending request to the MODBUS slave simulator in my PC with the following functions

Slave ID : 0x01
function : 0x03 // read holding registers
Address : 0x0070
Qty :0x001
CRC :xxxx

MASTER REQUEST :01 03 00 70 00 01 85 D1

I am able to send the above request successfully..
but my slave is sending response as

SLAVE RESPONSE 01 83 02 C0 F1


I checked the exception details i.e 0x02
but could not able to understand...


0x02 : Illegal Data Address:

The data address received in the query is not an allowable address for the server (or slave). More specifically, the combination of reference number and transfer length is invalid. For a controller with 100 registers, a request with offset 96 and length 4 would succeed, a request with offset 96 and length 5 will generate exception 02.

the locations i have to read is (0070h - 007Fh) and (0400h - 040F)(as per data sheet from client)

may be i am not able to figure out the exact address...

thanks in advance
 

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