How to measure rotational speed (RPM) using USB DAQ with DASYLab

[Fukuda]

We would like to measure the rotational speed (RPM) of the fan. Can you give me 4 points of advice for this? The fan outputs a signal of 5 mA when operating, and 0 A outputs when it stopped. Also, a pulse wave of Max 13V Min 0V is generated once every time the fan rotates.

#1. Is this possible with DASYLab?

#2. Can DASYLab calculate the average number of revolutions per unit time?

#3. Can DASYLab set up a system to issue an alarm when the rotation speed falls below a threshold?

#4. Could you please advise me on the best DAQ model to measure this? Is it USB-DIO32HS?

Thanks,

[JRys]

Please attach the fan datasheet or provide a link to it.

 

 

[JRys]

The USB-1808X has two counter inputs that can measure frequency. Use the Counter Input module set to Frequency. Multiply the frequency measurement by 60 to get RPM. Use the Combi or Sample trigger modules to determine when the RPM deviates.

[Fukuda]

I change my questions. A 5V pulse wave is input to the DAQ every time the fan rotates once. We would like to display the rotation speed [rpm] calculated from the number of pulse waves per minute on the PC display. When 60 seconds have passed since startup, the average rotation speed from 0 to 60 seconds will be displayed, after 60 seconds, the average rotation speed from 60 seconds to 120 seconds will be displayed, and after 60 seconds, the average rotation speed from 120 seconds to 180 seconds will be displayed. we hope to update the display every minute. Also, we would like to set off an alarm when the number of revolutions falls below a threshold.

#1. Should we use the two counter input function of the USB-1808X? Also, what kind of software should we use?

#2.  Does USB-1608FS-Plus support this?

#3. Is it possible to calculate the average number of revolutions per arbitrary time instead of 60 seconds?

[JRys]

There are two Counter types found on MCC devices, clocked and unclocked. The clocked counter is driven internally by a clock signal whose frequency is derived from a crystal-controlled oscillator. Because of this, it can measure frequency, period, and pulse widths. The other type of counter does not have a clock signal. This type is limited to counting pulses. The USB-1808X uses clocked counters, but the USB-1608FS-Plus does not. The USB-1808X counters can be read synchronously with analog inputs, but the USB-1608FS-Plus cannot.

For software, you could create a C or Python program that meets your requirements, or you could use the DASYLab software. I recommend the BASIC or FULL version of the DASYLab software. The FULL version is the way to go if you can afford the extra cost.

The USB-1608FS-Plus will not suffice because it has one counter input.

Use the USB-1808X and connect your fan signal to counter 1 & 2. Set Counter 1 to frequency and Counter 2 to totalize (count revolutions). Use the DASYLab Formula module to calculate RPM. An Average module can be used to produce various averages, which applies to both RPM and revolutions.