pid control configuration

[Vijay Khemka]

On 5/6/19, 9:20 AM, "Ed Tanous" <ed.tanous at intel.com> wrote:

    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.
    
Ed, we are not using cascade control here in facebook. We only use outer loop which gives data for fan to drive.
Is it possible to still run Phosphor pid controller with single loop?

Regards
-Vijay