I have connected a Slave Device to the MSD200. I am having problems reading INT and REAL variables. I check a value on the View Data tab, but the value doesn’t make sense. What should I check?

To read and log variables, it is important to know the endianness of the register, that means to know the sequential order in which bytes are arranged. The words transmitted via Modbus can be represented as big-endian or little-endian and they will be sent/stored accordingly.

To read and show REAL variables, it is important to know the endianness of the registers and bytes, i.e. register and byte ordering. It can be either big-endian or little-endian format.

If you use the big-endian format, the register or the byte that contains the most significant bit is sent first, followed in a decreasing significance order. The little-endian format has a reversed order.

You can select the endianness here: