FC 2 - Manual Set Constant (Signal Generator)

The output of the manual set constant is an analog signal developed within the function that is equal to <S1>. This function provides a tunable output value in engineering units.

 

 

Outputs:

Blk

Type

Description

N

R

User Selected Constant

 

Specifications:

Spec

Tune

Default

Type

Range

Description

S1

Y

0.000

R

Full

Output Value in Engineering Units

 

2.1 Applications

 

Scaler

Figure 2-1 illustrates how to use the manual set constant as a scaler. In the example, the transmitter has a range of 200 to

700 pounds per square inch. The range is scaled up 200 pounds per square inch by setting the manual set constant to 200.

The summer adds <S1> and <S2> to provide an output range of 400 to 900 pounds per square inch.

 

 

 

Set Point

Figure 2-2 illustrates how to use the manual set constant for a set point configuration. The transmitter range is ten to 20 inches of water. The desired set point (output of the summer block) is 15 inches of water. By setting the manual set constant to 15, the summer subtracts <S2> from <S1>. Thus, when <S1> equals 15 inches of water, output N of the summer block equals zero inches of water which shows the level has reached set point