About NI-6583 card DDC A usage

Hello,

I have Ni-7932 flexrio and newly bought NI-6583 DIO adapter card with CB-2162 IO board. I tried to connect adc with parallel 14 bit and ref clk out (100 MHz) to DDC A single ended pins and DDC A strobe pin. I used and redesigned "NI 6583 Continuous Acq DDR - External Clock"  example project. Normally When I run the example, I should have read 5 us pulse on SE pins but I have read almost 3.5uS. I don't know I missed any tricks about the usage of this module. 

Thanks in advance