Digital input to rpm

[ashnu]

Someone please help me with this... 

[JÞB]

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@ashnu wrote:

Thanks all for the reply : Smiley happy:

@@JÞB: The BNC 2110 has only CTR 0 OUT in the Trigger/Counter channel, so I don't know where to connect the digital output from picoturn to get a counter input.

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You really only need to click the "Device Pinouts" button in MAX

to find PFI8/P2.0 is CTR0 SOurce and on pin 37

Which puts it right here on the BNC 2110:

[ashnu]

This is the properties I am able to see with wat u suggested with Creating counting task with frequency.. 

Spoiler

[ashnu]

I am not able to see any of those values of M, B to be inserted here!

[JÞB]

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@ashnu wrote:

I am not able to see any of those values of M, B to be inserted here!

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From the DAQ Wizard

See that "Custom Scaling" Button Pull it down select "Create New..." Select Linear as the type and you get to this screen

M is "Slope" B is "Y Intercept" Type RPM in the Scaled units Box

[ashnu]

Thank you sooo much for such a detailed and clear explanation. But unfortunately I am not getting any signal when I rotate the turbine 😞

[ashnu]

I am very much sure about the proper connections with the hardware! Because it works very well with the digital Output (the LED glows when the turbine runs) but where as when I select counter input then I don't see any signal coming from DAQ Assistant., I have just connected graph indicator for this, but I dont see anything!!!!!

[ashnu]

Hey guys, 

I am back with the digital input as I am not getting any signal in counter input. So I used the VI given by Hooovahh.

I am having a problem at counting the number of rising edges. I saw the summation output was just 0 or 1 every time I ran the program when the turbine was running. The actual RPM reading in the instrument was 500, whereas I got just 0 or 30 rpm. 

How to rectify the problem near the counting of rising edges?

Your replies matters the most for me 🙂

[Hooovahh · Accepted solution]

So there was an issue with my VI but it sounds like you are having several troubleshooting problems and I suggest becoming more familiar with probes, to inspect the data to see where the problems is.  The VI I posted had an Or when it should have had an And in the compound arithmatic function.  So now the compound arithmatic should show rising edges where the value was low, then became high.  It then counts the number of times it sees this rising edge and does the rest of the math like normal.

Start by seeing if the data read from the DAQ is what you expect.  Then see if the number of edges are what you expect.  Keep going until you find where the data you get, isn't the data you expect and figure out why.

[ashnu]

Thank a lot for explaning me everything soo cleary and with patience. 

I did as you said and I came to kow that I am getting from DAQ assistant either all 0s or all 1s for the given samples (Ex: for 1000 samples, I get all 1s or 0s in 1000x1 array). If I am not wrong, I am suppose to get a mixture of 0s and 1s within the 1000 samples right?