voltage pulse outputted by inductive sensor lowered when plugged to NI 9401 for counters

Hi,

We have tested the voltage output the sensor XS618B1PAM12 with module 9401. When unplugged from 9401 the voltage output is approximately 5V and it is indicated by LED light on inductive sensor (see Pic).

When plugged to 9401 module the voltage output is around 0.46V and the indicating light on LED sensor is so weak. (see pic below). How can we resolve this issue, we actually need the inductive sensor to output the 5V voltage pulses?

Thanks.

Kodjo