DPlot

Hello, new to the forums here. Used DPlot to open some Tektronix WFM files. Worked awesome with the plug-in dll I found here!

I have some new LeCroy files. I saved it on a floppy in the scope as a binary format. The ASCII files filled up the floppy so I couldn't use that format. Any idea how to open one of the LeCroy files? The files were saved as SC1.000, SC1.001, SC1.002, SC1.003......

The Scope was a LeCroy LT584

Thanks

Did you try the Lecroy plugin? (On the Select File Type dialog, select L Plugins and Lecroy WavePro Files. If that doesn't work please send me a file or two, along with the anticipated time scale and min/max values if you know them.

Yes, I tried the LeCroy plug in but it did not work. I sent you the files via email.

Thanks!

Thanks for the files, but what didn't work about the Lecroy plugin? When I tried it I get 100,002 points from each file. On 2 files (SC1.000 and SC1.002) time starts at about -0.05 seconds with V=0, then there's a steep slope that decays down to V=-27 or so at 0.45 seconds. The other two files produce very similar plots; only the scale is a bit different.

Did you get an error message when using the plugin? Or do the plots not look like what you think they should look like?

Yes, I received and error message saying it was the wrong format. I'll have to check it later and give you the exact message and which plug in I used. I believe it was the only LeCroy one in the list.

Thanks!

OK, I tried it again and the files opened fine. I must have picked the wrong plug in. So next issue is the data is shifted 50ms to the left of the zero time. Anyway to shift it back?

Thanks!

The obvious answer is to use Edit>Operate on X with X=X+0.05 (seconds), or X=X-$XMIN.

But if the data in the file is really meant to start at 0 rather than -50 msec then the plugin is obviously misinterpreting something in the file. As with most of the digital recorder formats, documentation for the file format is hard to come by. But I'll see what I can find and, with any luck, correct this w/o breaking other files.

DPlotAdmin wrote:The obvious answer is to use Edit>Operate on X with X=X+0.05 (seconds), or X=X-$XMIN.

This is exactly what I need. I purchased the program not fully understanding how powerful it actually was. I needed something quick to plot my files out but I'm amazed at how powerful it is and all that it does!

Thanks!

As far as I can tell DPlot is interpreting the file correctly, unless the file format differs between recorder models. And if that were the case then the plot would most likely be completely fouled up, not just show an unexpected initial time value. The HORIZ_OFFSET member of the file header is -0.0500026 seconds, and that's the initial X value you get in DPlot.

Did you mean that you just wanted to get rid of that offset? Or that you know for a fact that the initial time value in the file should be 0?

I had the scope trigger set to -10V. Then turned the voltage supply on. So I was expecting to see the voltage go negative after time Zero. Am I wrong? In the plot the voltage is dropping before the zero time.

Thanks

All Greek to me; what I meant to ask was if you have some Lecroy application that plots the data or shows voltage vs. time values, and those results were different than what you see in DPlot.

I do see, though, that in all 4 files DPlot is showing -10V at t=0, if that means anything to you.

Well, I should have looked at the actual data closer before I stored it. Most likely, the set up of the oscilloscope gave me exactly the data DPlot is displaying. My task now is to figure out what I did to get it that way. Otherwise, the real answer of how quickly I go from 0 to -27 is displayed in the data so I got what I needed. I'll research the scope manual and I'm sure it will all make sense. I'll post anything I find.

Thanks!

Thanks, I'd appreciate your input.

Please don't automatically assume that I'm doing things correctly: almost all recorder manufacturers are notorious (in my opinion, but I'm of course biased on this subject) about their lack of documentation on file formats. Most of them sell their own data analysis packages and so aren't especially interested in providing information on those formats. There are exceptions, and other times I just get lucky with old docs provided by a user. Other times I pull my hair out. I'm not sure yet which bin Lecroy belongs in . I think I'm handling your files correctly, but I've certainly been wrong before.

No, you are correct in what you are displaying. This is the way the data was saved in the files. In actuality, the oscilloscope only has a time/div scale. There is nothing to say some waveform starts before zero. The data was saved this way in Lecroy's format.

The trigger i referred to earlier is a scope setting that enables the scope to only plot the waveform if the voltage goes more negative than -10V. I picked this value arbitrarily and could have picked, say, -5 volts. If I had picked +10 Volts, the scope would have not displayed any waveform at all since the waveform went from 0 to -28V.

So, since I had picked -10V, somehow the data saved showed this as the zero time. I have no idea why. I have bought several scopes from LeCroy so they'll be happy to explain it to me. Once I get the answer I'll let you know.

Here is the free LeCroy program I used to convert their data to ASCII:

http://www.lecroy.com/tm/Library/Softwa ... p?menuid=8

Perfect! This will come in handy if/when some other user has a different recorder model and I'm not sure which way is up. Thanks very much for the link.

Your welcome on the link. I talked to LeCroy and I didn't really get the answer I wanted. They told me that their data is stored with time zero starting at where my trigger is set. So, that's exactly what is shown in the data.

I have already fixed my plots shifting the data using the command you gave me above and the plots look great. Thanks again for the awesome support!