Please check the available PATI documentation and make sure that all the cabling and maybe external circuitry are working within the specs.
If you are sure that the problem is caused by the PATI hardware itself, you have to send the board back as described
here.
First please make sure that you run the latest version of the PATI related software from the
MathWorks "xPC Target" package. Based on the fact that MPL is
NOT directly involved in the "xPC Target" software development process, please send software related bug/problem reports directly to
MathWorks.