Pattern validation Specific HTML

I need to do the following: in an input text you will be forced to write 3 decimal numbers separated by (,) maximum 3 (,) and that only one "." for each number EXAMPLE:

100.10,100.20,100.30

I have tried it like this:

pattern="([0-9]{,1}[,])([0-9]{,1}[,])([0-9]{,1})"