CPU Usage

[fatjohn]

I have several vi's on a pc that have all of a sudden become painfully slow to use, on checking it appears that CPU usage is up to 99% the second one of the vi's is started. This is the case regardless of the complexity of the vi. Nothing has changed with the computer or any of the vi's that I'm aware of - one day they were working fine, the next they're all but unusable. I'm at a total loss to explain what's going on - can anyone shed any light??

I am using LabVIEW 7 with a W2K platform.

[LouisP]

Dear Fatjohn,

This is a hard question to answer. When running labview it takes the main thread and when there is 100% memory usage it then runs into virtual memory.

This is an unusual situation as previously you never had any CPU usage issues.

The main mistake people make is forgetting to put a wait until next multiple within the while loop of an application so it can switch tasks.

Another mistake is to insert configure e.g AI configure and also ai clear within a while loop instead of outside of one.

Below are links about reoccurences of CPU ussage issues:

http://digital.ni.com/public.nsf/websearch/8638139D6236D42086256A340073554A?OpenDocument

http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RNAME=ViewQuestion&HOID=5065000000080000002
41F0000&ECategory=Instrument+Connectivity.VISA

http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RNAME=ViewQuestion&HOID=50650000000800000037540000&ECategory=LabVIEW.LabVIEW+General

http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RNAME=ViewQuestion&HOID=50650000000800000011780000&ECategory=LabVIEW.LabVIEW+General

http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RNAME=ViewQuestion&HOID=5065000000080000008F350000&ECategory=LabVIEW.LabVIEW+General

Uninstall LabVIEW and then reinstall it and then as a last resort, you may have to uninstall and then reinstall. NI Serial and also NI VISA. This normally resolves this issue.

I do hope that this helps

Kind Regards

Louis Price
Applications Engineer
National Instruments