buffered loopback test

HI All,

I developed simple buffered loopback test DIO test vi using NI PCI 6536, VI is working fine without issues.but, Output data often is not same as input data.

though, same VI is working fine with PCI DIO 32HS and i am able to see expected output.

I am using Port 0& 2 for loopback Test, On board clock is the source of the timing synchronization.

Attached is the Vi which i had created using labview Version 2011.

Please give me suggestions/solutions as soon as possible. your help is highly appericiated.

Thanks

Durai S