ABB 2600T Series Instruction Manual page 106

106 2 6 0 0 T S E R I E S | P R E S S U R E T R A N S M I T T E R S | O I/ 2 6 6/ F F - E N R E V. E
Signal Characterizer Function Block (SC)
Overview
The signal characterizer block has two sections, each with an output that is a non-linear function of the respective input. The non-
linear function is determined by a single look-up table with 21 arbitrary x-y pairs. The status of an input is copied to the
corresponding output, so the block may be used in the control or process signal path. An option can swap the axes of the function
for section 2, so that it can be used in the backward control path.
Block Diagram
Description
The block calculates OUT_1 from IN_1 and OUT_2 from IN_2 using a curve given by the points:
[x1 ;y1 ], [x2 ; y2 ] ... [x21 ; y21 ] where x corresponds to the Input and y to the Output. The x-coordinates are given
in engineering units of X_RANGE. The y-coordinates are given in engineering units of Y_RANGE. The only useful mode is Auto.
Calculation and the curve:
OUT_1 is related to IN_1 and OUT_2 to IN_2 by the same curve, but there is no relation between IN_1 and IN_2 or between OUT_1
and OUT_2.
An output value may be calculated by linear interpolation between two points bracketing the input value.
Values of x should increase monotonically, so that interpolation may be possible. If not, a configuration error shall be set in BLOCK_
ERR and the actual mode of the block shall go to Out of Service. Write checks may also be implemented, but they may force the
order of entry of the x terms.