error using load from ascci

[Jen1]

this the file I am working on , it is something very simple but it's getting me mad , if you could help me I would thank to you all my life

[Phil_J1]

Thank you for that information, I had not tried to do this in LabVIEW. I need a moment to try reproduce this.

Phil

Message Edited by Phil J on 08-02-2007 05:46 PM

[Phil_J1]

Sorry for the delay, I had to install LabVIEW 8.2 with your version of SignalExpress.

I was still not able to get your error, however, when I ran the VI, the graphs on the Front Panel came out empty. Looking at the code, this appears to be a SignalExpress 1.1.1 bug. I checked the current release (which is currently SignalExpress 2.0) and this has been fixed.

Here is what I had to do to make data appear in the graphs:

1. using LabVIEW, open the file:

<your labview folder>\vi.lib\express\SignalExpress\Support\Simulation\ImportASCIISignal.llb\CG_ASCIIReadFile.vi

2. In the Block Diagram of that VI, look for the strings "%,;%T" and "%.;%T". Replace the "T" with "g" to make the strings be "%,;%g" and "%.;%g". Save the VI.

Let me know if that does or doesn't fix your problem...

Phil

[Phil_J1]

I was finally able to get your error by changing the language on my machine from English to Spanish. The reason that this produces an error is because the "T" in the string I mentioned before does not handle non-english machines well. Replacing the "T" with "g" does. When changed this on my machine, everything worked fine, even with Spanish as the language.

As I mentioned, this has been fixed in newer versions of SignalExpress, but the change I mentioned should fix you for now.

Good luck.

Phil

[Jen1]

Now I am able to work with my data file and  load from ascci  in LABVIEW, I wanna thank to you ,,,,

Thank you for the information and the time you spent helping me .

JEN

[Jen1]

Dear Sir :

I want you to please help me with another doubt. I am identifying a system with labview system identification . The problem is that we apply a stimulus signal and we have a response signal  that doesn't start at zero. The labview software identify the system but it assumes that our signal start at zero , what causes a not good identified model , could you help with  that??

I am looking forward for your help

 jeni

[Barp]

Hi Jen,

To do this operation, you need to remove the offset in the signal. In System Identification you can use the "Remove Trend" with the option "Mean" to make the signal around zero. This will give you a signal without a trend that you can use in the SysId.

Under examples, we have "examples\system identification\Getting Started\General.llb\Remove Trend.vi" that gives you an idea of what the functions does.

If this is not what you looking for, you can always two to use Statistics Function, define the Mean value and use this to remove the Offset from the signal (Offset and Scaling function).

Please let me know if you have problems with that.

[Jen1]

Thank you for your help , I did that and the identification is working better.

Jeni