PWM: Bulb/Fan doesn't turn off when stopping program

[Antaras]

Hello Labview Community,

I've made a small program PWM program in Labview. The user can control a fan or bulb, to get a desired temperature.

The fan and bulb is also regulated by their duty cycle (%). So far my program works as i want it to. But the problem is, that if I stop the program while the duty cycle is =100%, the bulb/fan doesn't turn off; it stays on.

But if i stop the program when the duty cycle is <100, there is no problem. The bulb/fan turns off with no problem.

Can anyone explain what's going on here, and what the solution is?

[RavensFan]

DAQ devices will continue to output whatever voltage it was last set at when you stop your program.  Chances are with your VI it is finishing with a voltage other than 0.

Just make sure you wire a 0 to the voltage out channels before you stop the VI.

[JÞB]

You may want to leave the fan on.

Shutting down cooling while a heating element is still smoking hot won't win you many friends at the local fire station.    Just saying...

[Antaras]

Thanks for the answer!

Even though it sounds simple, i can't find the voltage channel for my fan or bulb. Should it be at in the DAQ assistant icon?

[JÞB]

0 percent duty cycle would do.

A PWM always ends on an OFF state unless the darn thing is at 100 percent.  Bill is just used to typical analog voltage outputs

[Jenso]

Use the IdleState Property of your PWM channel to set it either to High or Low. Low should mean, that the PWM is "off" when the system is idle.