Variable of a M-Bus meter returns wrong value

It is possible that the data type of the variable mapped in the PLC is out of range (overflow). Change the variable data type (ST Type) to a larger range data type (such as lreal rather than real) in the data point properties, and upload the solution. Note that the variable GUID is changed after this operation.

Note: in the case of measuring unsigned quantities, it often helps to change the ST type to unsigned, eg from dint to udint.