Pulse count with a 9401 modules (cDAQ-9172 system)

[Irochka]

I'm trying to do a pulse counting by a 9401 module in a cDAQ-9172 system. I have three 9401 modules . One of them is working as a trigger (start-stop count) and the other two  (in slot 5 and 6) are for counting pulses from the 2 meters. It looks like a simple task but my problem is that I am counting always  3 to up to15 pulses less than my reference counter. everything points out to a task in my program is causing a delay. The question is where or what is causing such a wrong counting

[Johann.Wagner]

First for triggering with cdaq you must use the 9405 or 9406 (for analog triggering or 9401 for digital triggering) module in slot 5 and 6 - look in following link. Signals are routed with the chassis PFI Lines and only available at Slot 5 and 6.

http://digital.ni.com/public.nsf/allkb/851828B06A20E01B862571DA0005591A?OpenDocument

http://digital.ni.com/public.nsf/websearch/EFD808DC883F095186257170005A634D?OpenDocument

Then the other moduls in other slots can be configured with these pins for triggering. When you wants triggering on both edges you can look in following link:

http://forums.ni.com/ni/board/message?board.id=170&message.id=248456&requireLogin=False

 Best Regards