El5101 possible overflow?

Hello 
I have a spindle encoder with a quadrature signal. 
It will be wired to a El5101 but I'm worried about a possible variable overflow as I have 2000 ppr and my spindle can go up to 3000rpm. 
I don't think I'm the first one in this situation. How I can handle it? 

Thank you for your help 

There is a related thread here:

forum.linuxcnc.org/24-hal-components/581...oat-precision-issues

The conclusion is that there is not an issue.