Problems with Tektronix Open Choice desktop software

Dear readers,

here I like to ask about experience on a problem with Tektronix measurement software.

I am working as researcher at an accelerator lab.

For measuring, we use Tektronix oscilloscopes TDS3xxx, which have a LAN connection. This should be quite convenient, because data storage via LAN is faster than storage to internal floppy disc.

So far, I had good experience with the data (stored as comma separated values, CSV) stored to floppy disc. The only disadvantage is, storing of 10000 points with 4 channels takes more than 1 minute.

Now with the Tektronix Open Choice Desktop software, it seemed, speed can be improved. Saving is much faster. But looking at the data on the hard-disk of the PC where the data had been transfered, I was deeply disappointed. Compared to the data on floppy, the data transfered by LAN and Open Choice Desktop software was at lower resolution, e.g. substantial information was lost.

a) the time scale (x-axis) is to coarse The accelerator needs 20ms for the acceleration. If one wants to see what happens in the middle of the acceleration ramp, one uses a trigger delay of 10ms. And the Scope will then sample 10000 points at 5Gsamples/sec. Each point is then on a 0.2 ns timescale. So the points are located between (10ms-1000ns) and (10ms+1000ns). The data stored to floppy follows this correctly. For each data point the time stamp advances by 0.2ns.

But not so with the Open Choice Desktop software. From (10ms-1000ns) to (10ms), there are 4 points, where the time stamp is the same, and then one point which is a 1ns step. From (10ms) to (10ms+1000ns) it is even worse. There are 499 points, where the time stamp does not change, and then a big jump in one point by 100ns. Of course, such a timescale is useless for serious analysis. One has to replace it with a corrected one.

b) The channel data (y-axis) has reduced precision Looking at the quantization noise from the samples, the noise of the data stored by Open Choice Desktop is higher than compared to the data of the same acquisition stored to floppy. Especially, when using the MATH function, several bit of information can be lost.

Last year, I contacted the person in charge of Tektronix in Germany and explained him about the problems. But he was not interested. He said I should contact the local representative in Japan. Talking about customer care. The representative in Germany did not understand that nowadays neither the scopes nor the software are localized any more. This means it is the same scope, if in Japan or Germany or US, just the power cord is replaced and the printed manual is in different language. And the oscilloscope language can be set by the user.

Same for the Open choice desktop software. There is just one program and the language setting can be changed at runtime. In other words, the representative did not realize that my measurement problem was not related to being in Japan. It can and will happen anywhere where Tektronix sells its products worldwide.

And this is why I am posting this to this newsgroup.

Well, he forwarded my request to the Japanese office of Tektronix, and they contacted me and I told them my problem with examples of the data again.

Also my Japanese colleagues talked to the representative there. And it happened - almost nothing for more than half a year!

As I noticed yesterday, there was an updated version of the open Choice Desktop software (version 1.5 -> 1.6) available, so I made a test-setup with a scope, stopped it, and saved the data

Still, data on floppy were good as expected. But the loss of resolution was same between Version 1.5 and 1.6. I was disappointed, because the announcement of Tektronix was that many issues in the saving of CSV files had been corrected.

Well, the problems are still there, and the numerical values between version 1.5 and 1.6 of the data are identical.

Now I am wondering - am I the only person who found out about the problem reduced data quality? Or are there (thousands?) of other Tektronix customers who still believe that their data saved by LAN and the Open Choice desktop software are correct, when actually the data is crippled?

I am waiting for comments. If interested, I can send some files which clearly demonstrate the issue.

Sincerely,

Alexander Schnase