USB6009 Digital Input : Problem to acquire logic signal

Hi,

I need to acquire 3 signals.
I use Digital Input from USB6009

2 signals (P0.0 & P0.3) are periodic square 180µs (UP then down)
The third signal (P0.2) is not periodic but has High Level during 90µs then low level during approx. 100ms.

With my program, I never see high state from non-periodic signal.
Is it normal ?