Run 2 PCI 6024E in parallel -- Dirty signals

Question

Hi everyone,
I have two PCI-6024E Cards in my system. I want to run them parallel in continuous acquisition mode (I need to monitor 12 channels in differential mode).
The VI works like this:
Two tasks are configured for continuous acquisition (Device 1 and 2). In a following while-loop I read a certain number of samples from both devices, do some calculations, and write an extract (2 Vals) to a log file. Loop starts over.
The problem:
When doing so I have false measurements 3 to 4 times a second. Strength about 70% of my input range.
Things I did so far:
Checking the circuitry by using an analog data recorder. Result: clean signal
Checking the channels in MAX (test feature). clean signals
If anyone has any suggestions they would be greatly appreciated
Peter
p.s. I attached a copy of the code
Attachments:
_BehrLogDevZone.llb ‏146 KB

Answer 1

Hello Peter,
first you should insert an error cluster to display the error (inside and outside from the while loop).
Then you should reduce the amount of data for example from 600.000 to 6.000.
You have 12 Channels with 600.000 values per channel and you save double values.
The function "Save Data" needs a lot of time.
You should try to open the file before you jump into the while loop.
In the while loop follows the write function and outside from the while loop the close function.