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“PID”mode (e.g. conductivity, available on “PRO” models only)
A proportional-integral-derivative controller (PID controller) is a control loop feedback mechanism (controller) widely used
in industrial control systems. A PID controller calculates an error value as the difference between a measured process
variable and a desired setpoint. The controller attempts to minimize the error by adjusting the process through use of
a manipulated variable. The PID controller algorithm involves three separate constant parameters, and is accordingly
sometimes called three-term control: the proportional, the integral and derivative values, denoted P, I, and D. Simply put,
these values can be interpreted in terms of time: P depends on the present error, I on the accumulation of past errors,
and D is a prediction of future errors, based on current rate of change.[1] The weighted sum of these three actions is
used to adjust the process via a control element such as the position of a control valve, a damper, or the power supplied
to a heating element.
Before enabling this mode configure the required parameters within “SETTINGS” -> “PID PARAMETERS” menu,
- Time INTEGRATIVE value (time needed to the controller to activate a procedure as answer to a plant’s change. E.G.: time
needed for pump activation when reached a set value. ) Default value: 60 seconds.
- Time DERIVATIVE value ( time needed to the controller to react to a plant’s status change. E.G.: if pH value in water
increase, the time integrative is the time needed to notify the change.) Default value: 3 seconds.
- MODE b (dosed chemical is used to increase conductivity) or - (dosed chemical is used to decrease conductivity)
Move to for previous menu and saving changes. Within “SETPOINT” menu choose the related OUTPUT then move
wheel to select PID MODE. Parameters to set are:
- RANGE
value. Range is the maximum PID value over or under which (depending on Mode+ or Mode-) the
controller will automatically switch into proportional mode
- SETPOINT
which is the optimal value to achieve.
Move to for previous menu and saving changes.
