LV8.2.1: Bug in U8-Control?

[OnlyOne]

Hello,
i´m not sure if this a already known problem what i have but read this:

I´m calling a c-dll-function in LV 8.2.1 which has a one of the parameters a U8-input.
I connected a numeric control with U8-representation to this funtion call and run it. (value is 0 for this parameter).
But it did not work all the time. Some hours later i connected a U8-constant to the function-call and guess what happened --> it works!!!
Seems that there is a difference between a U8-control and a U8-constant.

Someone here with the same problem?

[OnlyOne]

Hello again,
see attached example in LB 8.2 where it also occurs.
i simply try to sum to U8-controls and LV marks this as error.
But there is no error when using U8-constants.
Why?

[RavensFan]

Grab your upper plus function and drag it down.  You have another plus function with unwired terminals sitting underneath it.

[altenbach]

Easiest would be to click the broken run arrow, the double-click on the error in the error window. This will select the extra plus icon. Move it out of the way with the cursors to better see the problem or simply hit delete.

Of course now we need to find out what the problem was with the dll call. See if the error is due to a similar thing. If you have problems finding the error, attach the VI here.

[OnlyOne]

Thanks for finding the noob-error 🙂
Attached the real VI with the problem. It will not execute because of the missing DLL(s), but
perhaps there is something similar?

Message Edited by OnlyOne on 05-30-2007 01:35 AM

[OnlyOne]

Hello agein,
did someone check my attached vi? Is the calling of the dll correct in this way, or can there be a problem?

[altenbach]

Everything seems to be hooked up correctly, but we have no idea what the dll expects and if the connectors are configured right. We cannot test, because we don't have the dll.

Is there a reason you are not wiring the error output of the dll call. Maybe it wants to tell you something. 😉

If the VI works with an input from a diagram constant, but breaks if the only thing you do is right-click the diagram constant and change it to a control, someting is wrong.

Can you upgrade to 8.2.1?

[OnlyOne]

In my main-vi the error-output is connected, only in this example it is not.

The Vi by itself does not break when i use a control, but the dll-function has a different behaviour.
I dont have the sourcecode of the dll so i cant debug inside the dll.

When i use a constant then the dll-call works, when i use a control (both with value 0) then the returnvalue of the function says something like "0 is out of range". But this error message has nothing to do with labview, but is perhaps a hint that the passing of the 0 was a kind of incorrect.


Currently i created as workaround for the control a typecast with type from U8-constant and the output of the typecast to the dll-call. Then i also works.

The Vi in the main-computer is in LB 8.2.1, only the example is not.

Hmmm

Message Edited by OnlyOne on 05-30-2007 03:15 PM