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Analog I/O Components

Analog components wrap hardware INT variables and apply a configurable scaling and calibration pipeline to produce engineering-unit LREAL values.

AnalogInput

Reads a raw INT from hardware, scales it linearly, then applies calibration to produce an LREAL value in engineering units.

Processing chain (read): RawValue → Scale.Transform() → Calibrate.Transform() → Value

Extends: Component
Implements: I_AnalogInput, I_AnalogScalable, I_CalibratableLinear

Interface

Member Type Description
FB_Init(Name, Input) Constructor Input is a REFERENCE TO INT pointing to the hardware variable
RawValue INT (Get) Forced or actual hardware integer
Value LREAL (Get) Scaled and calibrated engineering-unit value
Scale I_AnalogScale (Get/Set) Linear scaling object; defaults to AnalogScale
CalibrateLinear I_CalibrateLinear (Get/Set) Linear calibration applied after scaling
CalibrateCustom I_TransformLRealValue (Set) Custom calibration transform (replaces linear)
Force E_ForceState (Get/Set) Unforced / ForceOn / ForceOff
ForceValue INT (Get/Set) Raw integer used when forced on

Example

VAR
    RawHw     : INT;
    Pressure  : AnalogInput('InletPressure', RawHw);
    Scale     : AnalogScale;
END_VAR

// Configure 0–32767 raw -> 0.0–10.0 bar
Scale.InputMinimum  := 0;
Scale.InputMaximum  := 32767;
Scale.OutputMinimum := 0.0;
Scale.OutputMaximum := 10.0;
Pressure.Scale      := Scale;

RawHw := 16383;           // mid-scale
// Pressure.Value -> ~5.0 bar

AnalogOutput

Accepts an engineering-unit LREAL command and writes the inverse-scaled INT to the hardware output variable.

Processing chain (write): Value → Calibrate.Transform(Reverse) → Scale.Transform(Reverse) → RawValue → Output

Extends: Component
Implements: I_AnalogOutput, I_AnalogScalable, I_CalibratableLinear

Interface

Member Type Description
FB_Init(Name, Output) Constructor Output is a REFERENCE TO INT pointing to the hardware variable
RawValue INT (Get/Set) Direct raw integer written to hardware
Value LREAL (Get/Set) Engineering-unit command; setting this triggers the inverse transform
Scale I_AnalogScale (Get/Set) Same scale object as AnalogInput
Force E_ForceState (Get/Set) Forcing support

Example

VAR
    RawHw  : INT;
    Speed  : AnalogOutput('ConveyorSpeed', RawHw);
    Scale  : AnalogScale;
END_VAR

Scale.InputMinimum  := 0;
Scale.InputMaximum  := 32767;
Scale.OutputMinimum := 0.0;
Scale.OutputMaximum := 100.0;   // percent
Speed.Scale         := Scale;

Speed.Value := 50.0;            // 50 %
// RawHw -> 16383 (inverse transform)

AnalogScale

Linear scaling utility shared by both analog input and output.

Interface

Member Type Description
InputMinimum / InputMaximum LREAL (Get/Set) Raw value range
OutputMinimum / OutputMaximum LREAL (Get/Set) Engineering-unit range
Transform(Value, Reverse) Method Scales forward (Reverse = FALSE) or backward (Reverse = TRUE)

Implements: I_AnalogScale