RTU Wrong CRC

[sflalex]

Dear all
It's the firs time that we have used this application, but we have a lot of years using others like ModbusPoll or ModScan32, and the slave it's the firs time that we had communicate too.

The comunication is done by a Master ussing laptop by Moxa Uport 1150 and 1 slave by MGS-408

Comunication by Modbustools

• The 1st configuration of the expected register address but the slave doesn't read the correct function etc.
  The information about Modbus Tool is CRC Wrong.

• The 2nd has modified the register address to achieve the same read data from slave than on working applications, but logically for us was wrong because we put 4x etc. (there are images about configuration)
  The information about Modbus Tool is CRC Wrong.

Comunication by ModbusPoll / ModSca32

• The data is working (live value)
• The configuration of bus it's ok because its reading data (Modbus RTU 2W, 9600 bps, 8 Bits Data, 1 Bit Stop, Parity = None)

This is the 1st configuration of Modbus Tool (register address as expected of other programs, but yoyu can see how the data is read by the slave) [Communication KO]

This is the 2nd configuration of Modbus Tool (register address modified to read in the slave the same configuration as working communication with other applications) [Communication KO]

Configuration working variable ModScan and Slave display diagnostic [Communication OK]

Configuration working variable Modbuspoll and Slave display diagnostic [Communication OK]

Thanks in advance,
Best regards.

[serhmarch]

Hello. This is an old issue that had been resolved few releases ago. So you just need to download the latest v0.3.9

[sflalex]

Thanks serhmarch, I will try on Monday. Do you know why the register address must be modify like datasheet Function 03 register 40017 --> must be Register 440017 ? I never had to modify any register address before like this. Thanks.

[serhmarch]

Hello. If I understand correctly 40017 is holding register with number 40017 (numeration from 1). Left digit 4 (most signified digit) in ModbusTools address notation is just memory type id. 4x - for holding regs, 3x - for input regs etc. So 440017 can be interpreted like holding register with number 40017 (numeration from 1).

There is a similar thread: serhmarch/ModbusTools#5 (comment)