snap7.util.get_real() delivers inaccurate value

[joerggm]

Hello
I read and write to S7-1500 with no issues. But to extract a REAL value out of a bytearray I get an inaccurate value.
Example:

S7-DB value	get_real()
0.1	0.10000000149011612
50.0	50.0
50.1	50.099998474121094
49.9	49.900001525878906

Do i have to accept this or am I doing something wrong?
I want to save values in sqlite database.

Thanks in advanced.

[swamper123]

You haven't done something wrong. This is the nature of floating point numbers. (
Siemens said, you can be 6 digits accurate on a PLC.
Then you got snap7 and pyton-snap7 in between and the floatingpoint error exists.

Try out this in your pythonconsole:

>>> 1.2-1.0
0.19999999999999996
>>> 

For more infos about this error: read these python docs