jerseydevil

No driver yet, but it is only a matter of time.

:beer: Enjoy the end of summer BBQ's :thumbup:

I, too, don't see any limitations with Labview. I was just recently looking at USB and now I see that they support it in the newer release. NI has been excellent and Labview has provided half a career for me now. I guess it's funny that when you can find something that really works, its easy to just dig in and stay productive, and not even look up. Labview=Productive. I see from your click link that NI has become very "signal oriented". This seems like the best approach for most test engineering.

Interesting to note, thank you. I also came across another interesting deviance. The Formula Parsing requires ^ for exponent while the Formula Node requires **.

I was trying to be able to read in formulas from files into the formula nodes but it doesn't seem to have a way. Does anyone know of one, or do I have to continue using Eval?

I'm maybe overly familiar with the complex palatte, even have used the complex linear algebra palatte. One of these days I may even work my way up to the advanced complex linear algebra palatte. I use switches and do the 2 port stuff. I thought this was pretty common stuff, and I was finally ready to join the rest of the world by looking into how Labview handles it. The idea occured to me to look after I saw how many "waveform" functions they had.

Given the extensive application of s parameters and Labview's natural bias toward test and measurement, I expected a treasure trove of functions and features, not a totally mute package. Are s-parameters actually patent protected? Blame it on the 60's. And NI is too cheap to pay those royaltys?

The smith chart is a typical display function for s and t parameter arrays, but it does not imply any specific format for representing logical groups of s parameters such as the typical multiport s parameters, it just displays complex arrays. I already measure, read in, and manipulate large groups of s parameters from Network Analyzers although up until now these are mearly a collection of arrays, in some cases multidimensional arrays that are formed in an s parameter layout.

The newer analyzers like the Agilent E5071B naturally operate on multiport s parameters and t parameters, so I started looking into how Labview would represent such data, and was surprized to find nothing. It is clear that direct matrix multiplication and the other matrix operations can be used on 2 dimensional complex arrays, thus implying the correct form for a multiport s parameter data structure, however Labview has no support for typical things like impedance transformation and t parameter conversion.

They certainly have quite a few complex matrix math functions, but I was very surprised to see that it (at least Labview 6i) is virtually mute on the whole issue of s parameters. I don't mind cooking my own, but I think it is always better to work as a community. I was also surprised to find nothing about this in LAVA.

I started looking for program examples of how best to represent multiport s-parameters and t-parameters in Labview and was surprised to find only the definitions in the NI dictionary. I expected to at least see some common 2-port s-parameter programs, but couldn't even find any of these. Is no one doing any of this, or maybe I'm just using outdated terminology?

:headbang:

In your example you build an array of 1000 elements which you wire to the input (f) of the formula node.

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Well, thank you for pointing that out. I can see it should be obvious. I've got to stop that late night programming, or maybe the company should be hiring younger engineers.

:headbang:

I think this should conclude this lame post thread, unfortunately I'm not sure how to perform such a feat. Any last minute tips for me?

Your problem lies there, that the formula node requires a single value instead of the array. When using LV6.1 I get a strange error report ("Left brace required"???), in LV7.1 the error reports the real problem.

Didier

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I still seem to be missing some point. Where is the array in that formila node?

I have been trying to write LV 6.1 formula nodes and they keep breaking with a nonsense message about the wrong line and needing a left brace. Even simple ones like the attachment do this:

Error on line 1 is marked by a '#' character: "if ( f <# 250 ) CHRL=20; else CHRL=2; P"

First they work, then they don't work.

I don't see any info here or at NI. Has any one else seen this?

Download File:post-1810-1111114173.vi

Morality is in the eye of the beholder (well,,, maybe in the eye).

Thanks for the post, because it reminded me of an egg I put in a few years back that I forgot. It was the development team photo. Just a little waisted time, but a decent motivator and reward. Unfortunately I forgot the key.... I probably can't find the source, so guaranteed I'll spend all night clicking that CD.

gnite,

jd