fan PWM controll with NI 9401

[nhanthanh]

i have NI 9401 and cDaq 9178, i would like to control fanspeed with PWM for 4 wires fan.

I have tried many time but all nothing happen (VI works well but notthing change from the fan).

i use pin 19 from 9401 to send output to the fan.

any help, please.

[ELNO]

Hello,

I need more information regarding how you are connecting the cDAQ to fan, still You can try below mentioned step for the trouble shooting.

1.Run the code and don't connect the fan,In the output pin of cDAQ verify weather you are getting pwm generated or not? 

2.Check voltage level of the FAN PWM input and output of cDAQ is matching? cDAQ will give TTL Output Is fan pwm input also accepts ttl?

[GerdW · Accepted solution]

Hi nhanthanh,

I have tried many time but all nothing happen (VI works well but notthing change from the fan).

Did you check the output of your NI9401 with a scope or similar? Do you receive any pulses at that output?

Did you use MAX to check the NI9401? Did you use MAX to "play" with your NI9401 and to generate some test signals???

i use pin 19 from 9401 to send output to the fan.

Pin 19 is DIO3 according to the manual.

Did you choose the right counter channel? There is no default value in the "counter" control…

Did you also connect any of the COM pins?

On your VI:

What's the point of the sequence structure?

For how long does the VI run? How fast is the DAQmx task done?

[nhanthanh]

hi Elno,

thanks you for your help.

the VI is working now, and i can change the fan speed.

[nhanthanh]

Thanks GerdW,

the VI is working now.

yes, the vi works with the scope. and i can change PWM for the fan now.

i used pin 19 because i use counter 0.

i use flat sequence to help me adding stuff later without messing VI.

my VI run with continuous sample.