Underfloor Water heating - Night lowering

[Bobby]

Hi!

I am using PID script for UFH. And i want to have 2 adjustable setpoint temperatures for day/nighttime.
is this possible? 
Another alternative is to use the current setpoint temperature, but lower it by ie 4 degrees in night time.
My current script:

-- init pid algorithm
if not p1 then
  p1 = PID:init({
    current = '1/5/41',
    setpoint = '1/5/21',
    output = '1/5/1'
  })
end

[Erwin van der Zwart]

Hi,

You need to create a event based script that has 2 setpoints as input and a output that is given a value by the day/night logic to set one of the 2 inputs to the output. The output can then be used for the PID.

BR,

Erwin

[admin]

You can modify PID library compute function like this. Then you need to specify night_mode (boolean, true = night mode) and setpoint_night (float16 or similar) addresses in PID init. After that restart your script via enable/disable so new library and parameters are loaded.

Code:

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function PID:compute()   local params, current, setpoint, deltasc, deltain, output   params = self.params   -- get input values   current = grp.getvalue(params.current)   setpoint = grp.getvalue(params.setpoint)   if params.night_mode and grp.getvalue(params.night_mode) then     setpoint = grp.getvalue(params.setpoint_night)   end   -- delta between setpoint and current   deltasc = setpoint - current   -- calculate new iterm   self.iterm = self.iterm + params.ki * self.deltatime * deltasc   self:clampiterm()   -- delta between current and previous value   deltain = current - self.previous   -- calculate output value   self.output = params.kp * deltasc + self.iterm   self.output = self.output - params.kd / self.deltatime * deltain   -- write to output   self:setoutput()   -- save previous value   self.previous = current   return self.output end