It doesn’t really exist and it doesn’t make much sense. What one does is separate the whole and decimal parts with a comma, but in the computer this is not how these numbers are represented. Binary notation was created to indicate how the layout physical data in the computer, so how does each bit in memory represent a number.
The floating point has no whole part and decimal part, it is a number that has a sign, a mantissa and an exponent, but as a single thing, so:
For the computer that’s what matters and it’s efficient that way. There is no separation, when you see on the screen you are just receiving a textual representation of something that is shown decimally and there yes has a comma to give indication of greatness.
I know there are some people who invented this nonsense of representing a number as binary without being binary, but that doesn’t make sense and so real things (Windows calculator) will not give credit to this.
Even other forms of representing integer and decimal part do not use comma as internal representation, the comma is a human concept for decimal numbers.
If you want more details has an answer here. Or can see on Wikipedia.