Linear Approximation Function Block With Array Data

Introduction

This article provides a general description of the attached function block (LinearApproximation.cxf) for use with CJ and CS-series PLC's. Similar in functionality to the APR(069) arithmetic process instruction, this function block is capable of using arrays of REAL data types with a simple implementation.
 

Overview

This linear approximation function calculates y=f(x) when f(x) is not linear. The Function Block calculates an unknown value for an input value based on an array of provided "table data" using linear approximation between two points of the array. For example, the red dots below represent provided array data. The x value of +35.0 would yield a result of +1900.0 as the calculated y value. More detailed information can be found in the attached pdf file as well (LinearApproximation.pdf).

NOTE: This article is intended to supplement official Omron documentation. The provided function block should be thoroughly tested before implementation and may or may not function in specific applications. The user assumes full responsibility of the configuration, integration, performance and application of the provided function block. For detailed information on the use and general configuration of Omron products, refer to official Omron manuals or contact your local Omron support representative.

Link:
http://www.myomron.com/index.php?action=kb&print=1381