First, I'm a complete LabView newb, so bear with me....I have about a total of 36 hrs actually using the software. Here's the problem. I have a very simple setup with a 12V DC motor which I'm measuring the motor voltage and using a hall effect sensor to capture the shaft rpm, which is through a gearbox and has a MAX of approx 105 RPM's at full voltage. The raw data is being capture with a cDAQ-9174 and I'm getting the voltage from the motor and sensor through an NI 9219 analog input. Capturing and displaying the motor voltage...no problem. Capturing and displaying the signal sensor....no problem. Getting the pulse width measurement from the sensor signal....there is the problem. I keep getting an error for the "mid-ref level was not crossed". What I did was take the raw signal, convert it from analog to digital just to get it to zero's and ones, then converted it back to analog so the pulse width measurement VI could analyze the signal. I cannot get it measure the pulse width so I can convert it RPM. I have messed with every setting on the pulse width VI and the timing and measurement VI and I keep getting that mid reference level error. I attached a screen shot of the setup and what I'm trying to do. Any help would be greatly appreciated. The test setup doesn't show it connected to the 9219, but all that would show is channels 0 and 1 with the pos / neg connections to ports 4 and 5.

ni.com is currently undergoing scheduled maintenance.

Some services may be unavailable at this time. Please contact us for help or try again later.

LabVIEW

Author

NVM, figured out the issue. The lowest value that VI will accept is 1.51 Hz. Anything below that generates the error.

Message 11 of 11

(595 Views)