LGT_STEP: Step value calculation for constant lighting control

Block LGT_STEP (FB820) calculates the present step value to achieve the brightness setpoint. The step value is used for block constant lighting control LGT_CTL1.

Functioning

[StepVal] = [StepFac] * Abs([Brgt]-[SpBrgt])

The step value is then limited by the minimum and maximum step value [StepValMin], [StepValMax].

IF

THEN

[StepVal] < [StepValMin]

[StepVal] = [StepValMin]

[StepValMin] <= [StepVal] <= [StepValMax]

[StepVal]

[StepValMax] < [StepVal]

[StepVal] = [StepValMax]

Input values

Pin

Description

Data type

Standard value

Engineering unit or text group

Min.

Max.

StepValMin

Minimum step value.

REAL

1.0

%

0.0

100.0

StepValMax

Maximum step value

REAL

10.0

%

0.0

100.0

StepFac

Step factor

REAL

0.01

% / lx

-3.40E38

3.40E38

SpBrgt

Brightness setpoint

REAL

500.0

lx

0.0

3.40E38

Brgt

Brightness

REAL

0.0

lx

0.0

3.40E38

Output values

Pin

Description

Data type

Standard value

Engineering unit or text group

Min.

Max.

StepVal

Step value

REAL

1.0

%

0.0

100.0

 

Process response

Standard (see General rules and information).

Troubleshooting

Standard (see General rules and information).