Bug 288472

Summary:	Date/Time support for ASCII files generated by National Instruments LabVIEW SignalExpress
Product:	[Applications] kst	Reporter:	Ben Lewis <benlewis003>
Component:	datasources	Assignee:	kst
Status:	REPORTED ---
Severity:	wishlist
Priority:	NOR
Version:	2.0.4
Target Milestone:	---
Platform:	Microsoft Windows
OS:	Microsoft Windows
Latest Commit:		Version Fixed In:

Description Ben Lewis 2011-12-08 12:23:02 UTC

Version: 2.0.4
OS: MS Windows

NI LabVIEW SignalExpress is a software package for acquiring, analysing, presenting, and logging data without programming (see http://zone.ni.com/devzone/cda/tut/p/id/5837).

LabVIEW Signal Express stores log files in TDMS format which kst currently does not support. It can however export to ASCII which kst can read, however kst currently plots the data against sample number. This request is for the kst ACSII data source to support the reading of this file type so that the x-axis is displayed in terms of time. Ideally the user would have the option to select between absolute time and time relative to the start of the test.

The exported SignalExpress ASCII file contains header information followed by tab separated data. The header contains the log start time and a sampling period "dt". From this information it is possible to calculate the time value corresponding to each sample.

I have attached three sample files. Additional sample files can be generated from within SignalExpress, which is free to download from here https://lumen.ni.com/nicif/us/evalsignalexpress/content.xhtml.

As far as I am aware this text format is specific to SiganlExpress and is not common to other NI products such as LabVIEW. There are even variations in the formatting within SignalExpress depending on how the file is exported. See this link http://forums.ni.com/t5/SignalExpress/Single-Express-Export-to-Ascii-Not-logging-time/td-p/804903. Note the option to export the time column, as discussed in this thread, is not available after the 30-day trail period expires.

From my point of view the ultimate solution would be for kst to support the TDMS format. This is used across all of NIs software and would enable plotting of live data. However, I'm under the impression that this is a much bigger task than supporting the exported ASCII format so this would be a good intermediate solution.

Please let me know if you need any more info.

Reproducible: Didn't try

Expected Results:
NA

Comment 1 Nicolas Brisset 2011-12-08 21:18:11 UTC

Regarding proper TDMS support, there is apparently a detailed definition of the file format available here : http://zone.ni.com/devzone/cda/tut/p/id/5696 so I wouldn't be surprised if some people have already written a library to read and/or write this format even though so far I have found only a python open-source implementation (http://sourceforge.net/projects/pytdms/). 
If we have such a library, adding support for kst would be very simple.

Comment 2 Nicolas Brisset 2012-02-08 20:40:46 UTC

I'm currently trying to define a new ASCII config widget to add generic support for ASCII formatted time stamps.
I'm trying to look at the requests we had in the past to make sure that everything would be properly supported. You mention in the initial report that you attached some samples but I can't find them. Could you please post the first lines on the kst list, or attach them here?

Thanks