Hi all,
I´m a freshman with NI and need some help. I have a PWM-fan (DC, datasheet below) that I want to control with MATLAB DAQ tool box using NI DAQmx. The fan itself has 4 cables: +, -, sensor and PWM. I connected the + and - to an external voltage source (24 V, max. 3 A).
In my NI DAQmx chassis there are boxes of NI 9213, NI 9216, NI 9219, NI 9263, NI 9239 and NI 9481.
The sensor cable I connected to the NI 9239 (positive channel) as it is an analog input card. In Matlab I set it to "voltage" but I´m not sure if this is right. To the corresponding negative channel I connected te mass (-) that I split from the voltage source.
Without connecting the PWM cable I get a signal from the fan through the sensor cable that looks like the picture in the appendix. When I change the voltage in the voltage source, the signal changes. So that´s a good sign aI guess.
My first question is: what do I see in the graph? - Is it a voltage / current / ... ? Or am I wrong and used a wrong NI card (maybe it has to be a digital input card?
Further, how do I connect the PWM cable? Just the one cable to a digital output (that I don´t have yet?)? Or is there a way to connect it to a analog input?
Do you have any code ideas how to control the fan with PWM signal in matlab?
Any help would be so great!
Thanks and regards,
Hanna
