EXCEL CARE CONTROL ICONS9 74-5577–33 (US)EN2B-0184 GE51 R0518 (Europe)INTRODUCTIONPurpose This manual provides descriptions and application examples for control icons inExcel Computer Aided Regulation Engineering (CARE) software. You use controlicons in the CARE Control Strategy function.The control strategy for a plant consists of control loops that monitor theenvironment and adjust equipment operation to maintain comfort levels. Forexample, a control loop for an air handling system can turn on a return air fan whendischarge air temperature in the return air duct is greater than or equal to 68F (20C).Control loops consist of a series of “control icons” that dictate a sequence of events.Control icons provide preprogrammed functions and algorithms to implementsequences of control in a plant schematic. Examples of control icons include aProportional-Integral-Derivative (PID) function and a Maximum function (MAX).Assumptions This manual assumes you are familiar with the CARE process, especially the controlstrategy and switching logic functions. See Excel CARE User Guide 74-5587 (US) /EN2B-0182 ( Europe) for details and procedures for the control strategy andswitching logic functions.Temperature Differentials In the English measurement system, degrees Fahrenheit (F) usually represent boththe temperature measure and the differential measure. Dialog boxes shown in thismanual represent temperatures as °F and differentials as F Deg.Manual Organization This manual contains the following chapters:This Introduction lists other technical literature related to control icons, describes thedialog boxes related to control icon operation, and provides a table that summarizesthe available control icons.The Alphabetic Reference chapter describes each control icon. The beginning ofthe chapter summarizes the type of information provided for each icon.The Examples chapter describes applications that combine more than one controlicon to perform functions. These examples are in addition to the individual examplesfor each icon in the Alphabetic Reference chapter.Appendix A: Parameter List Description provides information about the parameterlist file generated by CARE when a plant is translated. This file documents theparameters used in the control icons and switching logic tables. It is useful duringplant testing.Appendix B: STARTUP User Address describes how the STARTUP user addressworks and how to use it in control applications.
