Using NI 9401 with cDAQ9174 for RPM Measurements: How to Output 5V for Power While Acquiring RPM

[FT1989]

Hi,

I'm new to LabView and how to use these modules. I want to use a digital hall effect sensor to measure the RPM of a rotating shaft.

How do I output a continuous 5 volts from NI 9401 to power the sensor, while also acquiring the measurement?

Steps I need to take:

1) Generate 5V signal on output line to power the sensor (sensor can be powered from 3V to 28V).

2) Acquire digital signal from sensor on a separate line on the module.

3) Convert digital signal to frequency.

I've tried working through DAQAssistant to generate an output signal. All it gives me when I set up a Digital Line Output is a checkbox to Invert Line. I set the Generation Mode to Continuous Samples, and that is all I changed. Where do I go from here? Once I get the 5V power to the sensor, do I need a separate while loop for the input line or can everything be in one loop?

Thanks in advance!

[Mario_C]

 Hi,

Have you tried to run the LabVIEW examples? Some of them are related to the steps you need to complete.  Go to help>Find Examples and search for these examples:

1- Voltage (with events) - Continuous Input

2- Thermocouple Continuous Input.vi

For the digital signal check this tutorial:

3- https://www.ni.com/en/support/documentation/supplemental/21/frequency-measurements-how-to-guide.html

I hope that helps.

Mario

[FT1989]

The first two examples use analog signals. I have the NI 9401 which is a Digitial I/O module. I've looked into some digital output examples as well but none that can force a specific voltage. If it can't be done, I'll connect the sensor to a 5V battery. I was just hoping to connect it to the module to keep the hardware setup clean.

I haven't gotten to acquiring the signal yet but that tutorial seems helpful!

[mcgraa98]

What port do you have the 9401 Module located in on the 9174?