error 200141 on parallel angular measurments

[tsunami]

I have been perusing the discussion pages on this error but so far the suggested resolutions have not worked.  I have included my top level VI as well as the necessary sub-VI's in a zip folder.  On the block diagram the CASE structure in question is "RELAXATION Mode".  There are 2 ZIP folders: 1 for the case that does not cause error 200141 but poses CPU load problems & the other that uses QUEUING but that excites error 200141.

A synopsis of this VI is that there are 2 counters reading angular position from 2 motors in parallel.  In conjunction with the counter tasks is a DAQ READ which reads in 2 analog signals from the 2 motors indicating the amount of torque being applied.  Once the counters & signals are read they are processed by a PID controller VI & the controlling signal is sent out by a DAQ WRITE.  The counters, READ, & WRITE tasks are all synched by the sample clock for the WRITE task & reside in the same loop.  Unfortunately, the WRITE to FILE & WAVEFORM CHARTS VI place a significant burden on the CPU that the loop iteration rate is seriously impeded.  To reduce that burden I added a parallel loop & employed QUEUING to file & display the data.  This resulted in significant control enhancement of performance.  However, error 200141 intermittently pops up especially if the user makes changes in the PID tuning parameters.  This error does not manifest itself on the VI that does not have the parallel loop with QUEUING.  I would like to employ QUEING but cannot avoid this menacing error!!!!!

SUGGESTIONS???  Oh, by the way I am using a USB 6229 DAQ so DMA is not an option & the top level VI's are "Integrated servo control".  If you reply with any VI's I am using LabView 8.5.1

[tsunami · Accepted solution]

One other possibility that I am currently exploring but have never implemented before is that when error 200141 occurs the VI does not terminate properly; therefore, all tasks may not actually STOP or CLEAR.  Is there a manner in which to ensure the tasks are CLEARED prior to execution of the loop & could this be a source to the error 200141?

The VI "without the problem" as far as I can tell always terminates correctly even if some intermittent DAQ error occurs.

[tsunami]

not sure what I did on the reply but somehow I selected something that indicates this has been resolved & it is NOT!!!

[lab_boy]

Hi tsunami,

The code you posted is too big to decode . Can you put smallest possible code which reporduces that error will help not only me but everyone else to help you. One tip, put the error indicators at the end to that you can see which tasks actually errors ou or can run in highlight execution mode, to see what is actually going on. Also how often you get the error as you mentioned the error intermittently pops does that happens when you start.

lab