DAQ for number of pulses using Field Point

[zl]

I have a water flow meter, which outputs pulses. I use a counter to connect it and read the data. I am wondering how to use field point to collect the data (number of pulses).

Thanks.

[Marni]

Dear Zl,

Take a look at this example. It was created for the [c]FP-QUAD-510, but it will work for other modules as well. If you are only reading in 16-bits, you don't have to use the index array VIs to manipulate the data after the read. If you have further questions, please include which fieldpoint modules you are using. Have a great day!

Sincerely,

Marni S.

[zl]

Marni,

Thank you for your help.

I have a FP-AI-110 and I tried to use it to get the pulses. Was it aproporiate? Do I have to buy a FP-QUAD-510 or FP-CTR-500 module?

If I need a FP-QUAD-510 or FP-CTR-500 mudule, how can I decide which one I need?

Thanks.

[Marni]

Dear Zl,

Counting pulses is much easier with the FP-QUAD-510 or FP-CTR-500, but can be done with the FP-AI-110.  You can't directly count the pulses with a FP-AI-110, but you can do it in software. Bring in the data by doing a normal read. Then, using shift registers, if the previous voltage is less than .8V (low) and the current voltage is more than 2.5 (high), increase the pulse count. I have attached a program that shows what to do with the data once you bring it in. I took the data from an array outside the while loop, but your data will be brought in one point at a time inside the while loop. One thing to take note of, since Fieldpoint brings in data at 1 kS/s, this will only work with pulses slower than 500 Hz. The farther the duty cycle is away from 50% duty cycle, the slower the signal must be in order to catch the pulses correctly. Please let me know if you have any questions. Have a great day!

Sincerely,

Marni