Owner's manual

10-3
Signal Characterizer (SGCR) Function Block
Block Execution For any given input value, the SGCR block determines where the input
lies in CURVE_X and calculates the slope of that segment using the
point-slope method:
Using this formula, the block derives an output value that corresponds
to the input. When the input lies beyond the range configured in
CURVE_X, the output is clamped to the corresponding limit in the
CURVE_Y array.
CURVE_X Values The CURVE_X values must be defined in ascending order. The X1
element must be the smallest value and each following X value must be
larger than the previous X value (see Figure 10-2). If the X values are
not configured in ascending order, a block alarm is set and the last X
value that is larger than the previous one is used as the curve endpoint.
The curve in Figure 10-3 has an invalid definition because X3 is equal
to X4. Between these points, the Y value is undefined because it can be
any value from Y3 to Y4. In this configuration, the X3,Y3 pair becomes
the endpoint for the curve definition. To use the X4,Y4 pair, you must
designate X4 to be greater than X3; it cannot be configured as X3 = X4.
Figure 10-2. Example of Valid Signal
Characterizer Function Block
CURVE_X Values
Figure 10-3. Example of Invalid Signal
Characterizer Function Block
CURVE_X Values
ymxb+=
Where:
m: slope of the line
b: y-intercept of the line
fieldbus-fbus_26a
Y
(outputs)
X
(inputs)
(X1, Y1)
(X3, Y3)
(X2, Y2)
(X4, Y4)
Time
fieldbus-fbus_27a
Y
(outputs)
X
(inputs)
(X1, Y1)
(X3 = X4)
(X2, Y2)
(X4, Y4)
Time
(X3, Y3)