What is the best way to measure time elapsed?

[FMM]

I am trying to measure the time it takes for a shaft to stop spinning. I have a digital signal that starts the brake cycle, and another that turns on when the shaft hits zero speed. I currently have a PCI-6024 E, and a PCI-6601 counter timer board installed. Is there a way that I can use a digital start and stop trigger with a counter, count an internal timebase and figure out seconds elapsed? If there is a way to accomplish this, some code suggestions (examples) would also be greatly appreciated.

[JoshuaP]

Hey FMM,

If you are using LabVIEW there is a shipping example that is called Two Edge Separation Measurement (NI-TIO).vi

This VI counts rising edges, using an NI-TIO based device (e.g.: 6602). The counter increments its event count every time a pulse comes into its source input. The default is the internal time base. The counters only increments between the rising edge of the aux line and the rising edge of the gate. The current value of the counter is read when the counter is finished or an error occurs.

I hope this helps out.

Joshua P.
Application Engineering
National Instruments

[FMM]

Thanks for your help. That was exactly what I was trying to do.

[damha]

Hi All,

Is there any example for two edge separation measurement for board PCI-6035E  and for labview version 6.1?

If someone has, could you share with me.?  Thank you very much.

I tried to open two edge separation measurement example using labview version 6.1 but failed.

Thanks

Nazri.

[Otis]

Hi damha,

That example is a Traditional DAQ Example.  I don't have LabVIEW 6.1, but I easily found it by going to Help > Find Examples and looking for it under the Counter Examples (you may want to upgrade to NI-DAQmx Version 7.4 for Windows 2000/NT/XP if you can't find this example).

I tried to save my 7.0 copy to 6.1, but it gave me some warnings so it might not work.  Nevertheless I'll attach it and hope that it works for you.

Regards,

[damha]

Hi Otis,

Thanks so much for your information. I have tried to open your code as attached, can open but the problem is I can't measure what I want to do  because of PCI-6035E is NI-DAQ board . Sorry if I was wrong.

So, could you give me any idea to solve this and may be I need to upgrade my Labview version.

Thanks again.

Damha

[Laura F.]

Hello Damha,

That example referenced is for our Counter/Timer boards, the NI 660X.  You need to look in the Counter Measurements DAQ-STC in the Example Finder to find supported examples for your PCI-6035E.  However, your hardware does not directly support two edge separation measurements.  The NI 660X (NI TIO) and M Series do support this measurement type.  To use an M Series device, you would need to upgrade LabVIEW. 

However, I did find an example that uses two separate counters to perform a two edge separation measurement on a E Series device.  Hopefully it will work for your application.

Regards,
Laura