New firmware is available for the DI-160. The new firmware addresses inconsistencies between the documentation and the way the hardware actually behaves.
Based on the documentation, the following chart illustrates the expected results on State, Event and High Speed Counter channels:
As you can see, the state changes to ‘1’, an event is triggered, and a count is registered on a leading edge transition. No changes are registered on falling edge transitions.
The following chart illustrates the way DI-160s actually responded prior to 7/19/2012:
If you have a DI-160 that shipped prior to 7/19/2012, you can request a firmware upgrade (free of charge) by submitting a support ticket on the DATAQ website.