Float or decimal type for virtual parameters?

Hello there, im trying to create a virtual paratemer to store GPON ONT rx power which is usually a float with 2 decimals, ie: -24.25 and so on…
After looking at the source code i have found that only integer and unsigned integers are supported when it comes to numeric values.
I can of course store the parameter as a string, however, this does not seem to work for charts when trying to do <= or => comparisons…
What is the solution for this ? thanks!

Have you tried xsd:decimal as the type?