Pattersearch optimisation Integer variable

Im adapting a GA code for PS optimization. It works ok and faster than GA.

However it hits an error sometimes and Iv narrowed it down to it using real optimisation variables. How can I force integer variables?

To make the original GA code faster I made an input file of feasible points and the optimization variable is the index of the points from that file. In GA it was straight forwards to set integer only variable.