slow mydaq

[Mecalight]

Hi,

Have been trying to create some logic for controlling a conveyor-model with help of LabVIEW and 3 myDAQ's, instead of the usual PLC-setup.

We haven't come further than a few functions, then everything became sluggish.

The model consists of two soleniods pushing out plastic-rings, two conveyor-belts and some other sorting mechanisms.

When the plastic-ring passes X1 (see program below) solenoid Y1 should push out momentarily, but in our program it will be hitting in 1/3 attempts. The other 2/3 attemps comes with a delay of a second or two.

All in all, it seems that the combination of LabVIEW and more than one myDAQ is way to unstable and slow for replacing a PLC.

(Has been testing on two different Intel I5-computers, and all atempts are ideling CPU-load).

The program beneath contains a couple of subVI's for minimizing the space of easy logic, but we have tried to direct connect the inputs to the outputs, while the result remain the same.

[robertpf]

Hi Mecalight,

Have you used the Profile Performance and Memory window to monitor which subVI's introduces the lag? Take a look at this Knowledge Base on how to monitor elapsed time in VI's: http://digital.ni.com/public.nsf/allkb/45224de86d95bf30862574dc007caeab?OpenDocument

That will probably tell you where to start digging, but here are some general thoughts as well:

At the moment there are a lot of unused DAQ input VI's that still are called upon for each loop iteration, depending on the content of the "DAQ INNG. X [nr]" that may introduce some lag. Take away all unused code, will it increase the speed?

Another thing to try is using event structures to monitor value changes and minimize the amount of code for each loop iteration. 

Please upload your project files if you like me to further look into it.

Best regards,