Only N samples recorded to ASCII fil

[Stjepan]

This is also one of annoying things in Signalexpress. Every time i save data to ASCII file during continuous acquisition, only N samples are recorded. How to FIX this?

[OKors]

Are you saving to ASCII with a Save to ASCII step in RUN mode or are you using the RECORD method which outputs to a logfile?

If you're using the Save to ASCII step with RUN, be sure you've selected Continuous Samples from the DAQmx Acquire>Settings dropdown list. From there you have to check the "Overwrite then append to file" option. Also be sure to select Run Contiuously in the RUN option.

This is what I've had to do in order to have any start/stop control while acquiring test data, and still be able to maintain file naming convention. Some of our tests are a couple seconds, some are a couple minutes, but they're all dynamic so I never know how many N samples I'll need to capture all the data.

Be sure you rename your .txt file in the Save to ASCII step before logging another data set or it will overwrite your previous file (hence the overwrite then append to file option). Annoying, yes. I too am struggling with some of SE's features, or lack of... 

Message Edited by OKors on 09-10-2009 10:10 AM

[Stjepan]

Yes, it's all set like you said. But, maybe I said it in a wrong way, the problem lies somewhere else. I get repeats of N datalines. my time column goes like this if sample time is 1 second, an i request 5 samples:

0

1

2

3

4

0

1

2

3

4

0

1

2

3

4

Of course, al signal values are different, but time column is not so usable.. (for importing in matlab for example).

[OKors]

Can you post your .seproj file? I'd like to see how you've got your timing settings configured.

Also, what are your signal inputs?

[Stjepan]

First of all, thank you for sparing your time to help me.

This .zip file contains my log, se project and my ascii files.

I use 2 NI-6009 devices, one to measure current and voltage, other to measure 4 temperatures from Pt1000 sensors. Recorded signals are only noise, beacuse system was off at the time. But i think it doesn't matter. Just look the time column of Temp (sample time is 1 Hz):

0.0000E+0
1.0000E+0
2.0000E+0
3.0000E+0
4.0000E+0
5.0000E+0
6.0000E+0
7.0000E+0
8.0000E+0
9.0000E+0
0.0000E+0
1.0000E+0
2.0000E+0
3.0000E+0
4.0000E+0
5.0000E+0
6.0000E+0
7.0000E+0
8.0000E+0
9.0000E+0
0.0000E+0
1.0000E+0
2.0000E+0
3.0000E+0
4.0000E+0
5.0000E+0
6.0000E+0
7.0000E+0
8.0000E+0
9.0000E+0
0.0000E+0
1.0000E+0
2.0000E+0
3.0000E+0
4.0000E+0
5.0000E+0
6.0000E+0
7.0000E+0
8.0000E+0
9.0000E+0

Thank you in advance.

[OKors]

Hey, trust me, even if I can be a little bit of help I know how far along that goes!

While I'm loading your .seproj file let me ask what your acquisition needs are. In other words, are you looking to manually start/stop your data logging or do you need it to record on a trigger or some condition? Are you looking to capture ALL the data of a dynamic test or do you specifically need only N samples?

[Stjepan]

I want to manually start and stop the test, no triggers, and I'm interested in getting the WHOLE test in one file (or two files like here). Few minutes for example. And I want time columns to be formated like a timeline (in seconds).

[OKors]

So, the good news is I opened up your file and there's nothing wrong with your configuration. In fact I've been able to duplicate the issue on my own system using totally different signals and hardware.

The bad news is, this is a SignalExpress bug. I've been on the phone w/ NI tech support a number of time recently regarding other issues I've had with SE; I had a chance to talk to them just now and asked about your issue. They did inform me that it is a bug in SE and there's a Corrective Action Request already filed, so for future releases we may see a fix

Corrective Action Request (CAR)# is: 147319. The more of us file a car on this issue, the further up the priority list it will go.

So that being said, what I can offer up is that I've never had a need for a time column. In fact our engineers request we do not include it in our data file (they use mostly Excel to view compare, manipulate and report data). As long as they have the timing settings they can derive their own time column if necessary. Plus when you view the data in .txt or excel it's already in sequential order from the start to stop.

I know that's not the answer you want to hear but at least you know there is nothing wrong with your setup. I suggest filling out a CAR though.

Good luck! 

[OKors]

I forgot to add. The other workaround is to select Absolute Time in the File Settings options.

The format may not be exactly how you're used to seeing it but a simple formula in Excel could remove the non-significant digits.

For example B2 (=A2-55489xxx.xx)

So if your time column looked like this:

55489xxx.01

55489xxx.02

55489xxx.03

55489xxx.04

That forumla would make it look like xxx.01, xxx.02, xxx.03, and so on.

[Stjepan]

Dear friend, thank You a lot, I appreciate the help. I am aware of the things that may be done to "override" such a bug with simple counting lines and adding dt (sample time) every next line. But I like automated processes, and I am fascinated with Labview capabilities, so I tought that SE is also very nice piece of software to start with new NI products (I am ex-DASYLab user 🙂 ). Your suggestion is also good. To use absolute time.

Thanks once more 🙂

Stjepan