Raymond

Thanks Mark, it works. I'll definitely try to apply this to my project. Another slight complication is that I need to create a new file for data logging at midnight every day. I suppose if I do not open the file dialog at midnight, I'll be fine?

Thanks for your reply, but I'm not sure if I understand what you suggest... Are you saying that I should change some settings in 'VI properties' for all sub-VIs?

I'm seeing the same problem... So, there's no way around it?

I have two loops. One for data taking and logging, one for loading a parameter file. I notice that when I click the "browse" button on the "load file" field, the data taking and logging loop freezes. Attached is an example which demonstrates the problem. Thank you in advance! Raymond suspend.vi