data loss with DAQ cards

[ccodet]

Hi all,

I'm actually using two NI USB cards (6008 and 6216) to acquire measures with the analogic channels.

When I run the VI, I notice that sometimes I lose all the signals entering in the analogic channels (all the values are set to zero values).

The VI is composed of one loop for the acquisition and the computation, and other one for the saving of datas in excel file.

I join you the VI use for acquisition, the configuration file exported from MAX and a picture of the saving diagram.

I'm working in Labview 7.1 with NI DAQmx 8.7.1 drivers and Windows XP OS, someone could help me solve this problem ?

Thanks in advance.

[Romain_Duval]

Hello ccodet,

Thank you for posting your question on the NI forum.

I would suggest you to use the producer/consumer scheme to separate correctly your acquisition and your data treatment in order to not slow your acquisition:

http://zone.ni.com/devzone/cda/tut/p/id/5218 

here is an example of the producer/consumer scheme  used for acquire data and save them:

http://decibel.ni.com/content/docs/DOC-2431

By the way, which AI channels give you zero. is it the ones used in the small while loôp or the one used in the big while loop.

Sincerely

Romain D.

[ccodet]

Sorry for the time in the response. In fact it is the two which pass through zero. But the one in the little while loop more frequently that others.