pid control configuration

[Ed Tanous]

On 5/2/19 4:24 PM, Vijay Khemka wrote:
>  My understanding here is pid data are only defined for temp sensors which will generate pwm values for fan.
> 

The above is not how phosphor pid control operates.  The temperature
controllers "request" a given fan RPM, then the fan PID controller
(which is scanned much more quickly than the temperature controllers)
attempts to drive the fan to that speed.  This ends up being a two stage
feedback loop that can perform better than a single PID loop.

In control theory, this is called a "Cascade" control scheme

https://en.wikipedia.org/wiki/PID_controller#Cascade_control

-Ed