How can I view data continuously?

[Ted_H]

Hi Bill,

The functionality you are asking about, tracking an entire log, is available in the current release of LabVIEW SignalExpress 2.5 (released in August 07). 

Ted

[cwalmquist]

Hi Ted H,

I'm the person who started this thread, so I'm very interested.  Can you elaborate on what the capability is or point me towards some literature that describes the capability to view continuous waverforms as they are being acquired?  This has been a huge frustration for me.  I once again have a need for the capability, and will continue to.  I was not able to use my newly-puchased NI hardware on the job I mentioned in my first post because of this limitation. 

Thanks,

Charlie Almquist

[Ted_H]

Hi Charlie,

The capability I was refering to in my last post was the ability to view all your data while logging data.  To access this functionalty, you will need to set up a data acquisition step, and then log the data using the record button.  If you drag the data log into the data view, you will be able to see the streaming data as it is being logged.  Right click on the preview graph below, and select track entire log.  This will allow you to see all the data logged in the data view.  I have attached a screen shot detailing this.

There is an alternative method to view data history in SignalExpress, and that is to use the waveform chart.  In SignalExpress, the waveform chart is only available when the data acquisition mode is set to on demand sampling.  The length of the chart history can be changed in the Tools>>Options window under the data view tab.  I have attached a link to a KnowledgeBase article detailing this information.

http://digital.ni.com/public.nsf/allkb/62729F5063C1C5E68625728400563E5E

I hope this information helps, post back if you have further questions.

Ted

Message Edited by Ted H on 10-23-2007 11:22 AM

[William @ UofW]

Hello Ted and Others,

I have recently picked up a CompactDAQ system and SE (currently using ver. 2.5) to replace the older DAQ system my students and I used in research and in classes.  I was particularly interested in the questions which were sent forth regarding the viewing of data continuously on SE.  For your information, I deal with topics in solid mechanics and we often acquire data from an LVDT (or laser displacement transducer) and load cell to generate a force (ordinate) versus displacement (abscissa ) curve when we crush extrusions and/or other structures.  The problem we have is identical to the one described previously and the solution you have provided appears to work.  Unfortunately, when starting a new test the user of SE must go through the entire "tuning" process so as to have the complete data displaced in a consistent manner on the XY graph.

The older DAQ system (snapmaster) we have used illustrated the force/displacement data continuously which was really effective to quickly view the response of structures during large displacements.  Students really appreciated this approach to viewing observations from an experimental test.  Unfortunately I have not found a similar process, which does not require extensive "tuning" of the data view, in SE.

Is there a way to simply drag the signals (i.e. load and displacement signals (which are typically voltage)) from "acquire step" (and not logged data) to the data view and have the XY graph illustrate the sensor data continuously?  To the best of my knowledge (and I do recognize that I have much to learn about SE) this should simplify the process which you have presented earlier for showing continuous data from a log.

I sincerely appreciate any feedback or assistance you could provide.

Best wishes,

Bill