Program lost part of functions after 1.5 month?

[JÞB]

harry,

Now that we can see more of your code (NICE clean-up but it is not quite "software" yet but, "functional code" is worthwile)

If you replaced an old tradtitional DAQ "Wait +(mS) with CCI Delay.vi you are golden.  The old DAQ "Wait (mS).vi does have a known issue of entering an infinate loop when the millisecond timer rolls over.

A millisecond timer is just what it sounds like-  It counts the number of milliseconds since the core was restarted up to the maximum value of a 32 bit signed integer (about 49 days) and then it starts at 0 again.  So if you start a wait for "x" mSec after Rollover-"X mSec before" rollover you can't get there (And Wait (mS).vi never exits)  You have seen this before! Wait (mS) is the exact same code when compiled as a C "Sleep" instruction.  Your IT dept will tell you to log off at the end of the day (and they will push "Fixes" that force a reboot at least once per month) so you never see this in managed IT environments.

Coffee smells wonderful! unless it is poured hot into your lap.  sorry you got burned

[Harry.W]

Lynn, you are definitely correct about improving my program architecture. Apparently I need learn more to be able to do something like you mentioned. Thanks for your suggestions!

Harry

[Harry.W]

Raven Fan,

Thanks for your example! I already removed the tick count functions based on other suggestion, that's why you didn't see it. Thanks!

Harry

[Harry.W]

Jeff,

Thanks for your explaination. Yeah I agree this is definitely not a software, but rather just a piece of code. I'm happy as long it works! 🙂

Anyway I will take this as my fix for now and will update you guys next couple of months how it goes. Hopefully I don't have to report the same problem again...

Rgds,

Harry

[Harry.W]

Jeff,

I still kind of wonder why this timer issue can cause my Analog Inputs not working. When the problem occurs, all the Analog Inputs show "N/A" instead of current values (when operating normally, the values shown range from 4mA to 20mA). Does this make sense to you? Why no error message shows up? Any thoughts?

I just want to rule out all possbilities (probably not gonna happen but at least i tried). Thanks!

Rgds,

Harry

[JÞB]

Lookong deaper there may be other issues.  If Wait +(ms) hung the while loop would not iterate at all

On the oter hand if that AI task is contiouos acquisition you could get to a point where your buffer overflows you might not notice the error since your error is on a tunnel and not a shift register.

[Harry.W]

Jeff,

So for #1, the CCV delay vi should take care of the issue, right?

For #2, I didn't quite get it. Is there a fix for that?

Thanks

Harry

[JÞB]

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@Harry.W wrote:

Jeff,

So for #1, the CCV delay vi should take care of the issue, right?

For #2, I didn't quite get it. Is there a fix for that?

Thanks

Harry

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Is th AI Read Contineous? or is it configured to read x number of samples then STOP acquiring until you ask for more?

[Harry.W]

Jeff,

"Overflow" scares me!  How can I avoid the potential buffer overflow you mentioned here? Or is there a way to monitor buffer usage?

Do you mean I should put the error aslo as a shift register? Initially I don't even have a shift register for the task but someone suggested me to put there saying it will make sure I read and write the most latest data.

Forgiving my ignorance, but wouldn't shift register keeps storing more and more data? Do i really need it?

Thanks!

Harry 

[Harry.W]

Jeff,

At the moment, I actually read only 10 number of points each cycle. I thought the old version I used default value "-1" which should acquire 100 points every time.

Harry