Measure Digital Frequency-Buffered-Continuous-Large Range Two Counter

[Daryl]

Can someone please explain to me how this VI works?

https://decibel.ni.com/content/docs/DOC-11542

From the link "Note: It is important to set the Maximum and Minimum Values of your unknown frequency as accurately as possible so the best internal timebase can be chosen to minimize measurement error. The default values specify a range that can be measured by the counter using the 20MHzTimebase Use the Gen Dig Pulse Train-Continuous example to verify that you are measuring correctly on the DAQ device."

I'm trying to determine what the error will be in my measurement using this VI.

I am using a sensor to measure the RPM of a device that will rotate from 1,500-15,000 RPM. The sensor will provide a pulse every time a piece of reflective tape passes in front of it. I am currently placing 1 piece of tape on the device which gives me 1 pulse per revolution.

How can I calculate the measurement error using this VI if I set min Freq at 25 and max at 250? How is the "best internal timebase" chosen?

I am using an x series device for measurement USB-6343

Thanks.