Digital Tacho Using PCI-6143 (Not Working Properly With Phase And Magnitude Vi)

[Unknown123]

Hi,

I was using Analog Tacho Process VI for my order analysis toolkit with PCI 6143 and thats working perfectly my phase and magnitudes after converting to even angle are perfect.

the same task when i try with digital tacho (since PCI61423 Has Counter)  i get random phase readings which continues to increase to several thousands.

my speed profile is of i am getting the same RPM reading as i am feeding via function generator but my phase and magnitudes are not accordingly.

anyone faced this issue..?

one more thing i cannot use (Build Digital Tacho.vi) in event counting mode it gives me false RPM reading i tried building task from NI DAQmx like edged count for event count mode and frequency for period measurement this VI works only with frequency task and in period measurement mode only i cannot make it run to even counting mode.

Thanks.

[Cavarval]

Hello,

Can you provide information about how are you configuring the VI? Screenshots and even posting your VI would be helpful.

In the meantime you can see examples of how to configure this VI and use it in the Sound and Vibration Measurement Suite shipping examples. Please open LabVIEW and go to Help > Find Examples > Tookits and Modules > Sound and Vibration. There you will find the Log Data (Digital Tach, DDAQmx).vi in the File Input and Output folder using the same VI you mention and the Load Data and Perform Order Analysis (Digital Tach).vi for a possible post processing you might need to do in the Analyzing and Processing Signals > Order Analysis folder.

Note that in the Log Data (Digital Tach, DDAQmx).vi you will be acquiring an analog signal and using a counter for the events counting.

Please review the examples and let us know if you still have further questions.

[Unknown123]

HI, ThankYou For Your Reply I Will Post a ScreenShot Of What I am Doing...I configured it in period measurement mode there it works fine for some while.

i already have gone through the example you mentioned there is one VI which is    "SYNC DSA (..Smthng I Forgot)" and there are some properties like "Arm trigger" and some others that seems to be for synchronizing both tacho and analog channels i tried setting those for PCI 6143 but that gives an error stated like "this property may not be supported by your hardware"....

i am attaching the VI which require labview 2014 which i currently dont have i am using labview 2013 at my home so cannot open this vi for a screen shot.

kindly give it a look and tell me if i am doing it wrong or my card is supported for digital tacho or not..

thanks.

[nikale]

Hi,

There is one thing I noticed worth mentioning that could be leading to the error. In the bottom left corner of NI Example Finder there is an option for setting Hardware and limiting results to that hardware. When this is done it doesn't display the examples you've mentioned. Also, when you select an example the bottom right corner shows the requirements necessary for that specific example. There is a Waterfall and Cascade Plot (Digital Tach, DAQmx).vi that is compatible with the PCI-6143. It might be possible to manipulate the other examples you've mentioned to work with your device, but those examples aren't really intended to be used with that device. I hope this helps just incase it was something that might have been overlooked.

Kale W.

[Unknown123]

Hi,

Thanks for your time i had never gone through that option before..will try that waterfall example tomorrow and will let you know.

[Rauf_Jaleel]

Hi, 

I have undergone the similar problem but your suggested solution is not functional, chiefly because even though NI lists this particular example functional for PCI-6143 it don't allow you to select it as a DSA device type. Is this a misinformation on NI's part or PCI-6143 is simply incompatible with Digital Tacho Processing example?

Thanks

[Cavarval]

Hello Rauf,

Can you tell us where did you see the example is compatible with the PCI-6143 card?

The card will not be compatible with the Analog Input portion of the example (acceleration measurement) because since the example assumes a DSA device will be used, it configures some properties like Input Coupling and IEPE excitation, which are definitely not valid for the PCI-6143.

You could possibly have the tachometer connected to the PCI-6143 and get it working, but the analog input section will definitely not work unless you modify the example to get those properties out, but that could render the example unusable anyway; if the sensor you have requires IEPE excitation, you are going to need to provide it anyway and there is no way the PCI-6343 can do that.