Problem with formula waveform in LabVIEW 8.5

[JertoZ]

Hi

I was wondering if I am the only one with this problem.

I have installed LabVIEW 8.5 yesterday, and I'm not able to use the Formula Waveform.vi like before.

I was on LabVIEW 8.2.1 before and I was able to pass only the amplitude "a" as a variable to the formula input.

Now, in LabVIEW 8.5 I'm not able to do this anymore, the function return the following error: NI_MAPro.lvlib:ma_evalFormula.vi:3<ERR>
Invalid variable names.  Allowed variable names are: w, f, t, fs, a, or n.

Is it something that NI removed or forgot?

Is it voluntary? 

Thanks

[altenbach]

I can confirm that this is a new 8.5 problem.

If you dig down in the code, you can see that "ma_evalFormula.vi" does some extra song and dance to validate the formula, and it apparently fails for some valid inputs.

(Workaround: A formula of "a*t/t" would give your desired result).

Of course there are probably better ways to generate a "constant" waveform. 😄

Message Edited by altenbach on 09-14-2007 10:11 AM

[JertoZ]

I know it may not be the best way to create a constant waveform, it's was just easier for me.

I use a case structure to send the formula to the waveform generator and one of my cases is a constant.

Thanks anyway for the confirmation of a bug.

[altenbach]

I made a quick report in our monthly bug thread.

http://forums.ni.com/ni/board/message?board.id=BreakPoint&message.id=4179#M4179

Most likely, someone from NI will followup with a comment. 🙂

[JertoZ]

Ok thanks

[NoahR]

This was reported to R&D (# 4DGGKPQU) for further investigation.  Thanks for the feedback!

Noah R.

Applications Engineer

National Instruments