Global tasks (handler)

I have programmed legacy DAQ cards like the 6024 using LabWindows CVI for 15 years. Now I have to use a USB 6218 and DAQmx. I want to use a counter to measure my loop time. If I start a task (like start the counter) in one subroutine call I can not call that same task in another subroutine call (like read the counter). The task handler ID seems to only be a local variable. The task or taskhandler can not be made a global variable. If the create, start, read, stop, and clear tasks are all in the same subroutine, everything works. I hope I am stating this problem correctly, I am an engineer who knows some programming, not a pure programmer.

RobertoBozzolo,
First of all, thank you kindly for your quick response and help. I think you are onto the source of my problem. I have attached some information to explain the code. The program is very large. I thought I have defined the Task Handler at the system level with a static definition. But when I compile the code, I get a message that the task handler is undefined.
I hope I have explained my code in the attachecment well enough for you to see the problem.
I have to share with you that I have never used task handlers. Somehow, since CVI was started I have gotten by without out it. Right now I am not a fan of the DAQmx approach to data acquisition and control. I used to be able to use simple easy IO or legacy library routines that were very straight forward and used a minimum of code. I also tried defining the tasks in Measurement and Automation Explorer, but I could not get those to work also. I thought it was just me but I talked to two other engineers who also dabble in programming and they too are not happy with the improvement.
I think the issue is that we have to be better programmers. Instead of just engineers who use the CVI tool.
Again, I want to thank you for any help that you can offer.
Mike
Attachments:
Taskhandler issue.docx ‏22 KB

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