Honeywell AUTOMATIC CONTROL - Microprocessor-Based DDC Fundamentals; Microprocessor-BasedDDC Fundamentals

MICROPROCESSOR-BASED/DDC FUNDAMENTALS
131
ENGINEERING MANUAL OF AUTOMATIC CONTROL
Contents
Introduction ............................................................................................................ 133
Definitions ............................................................................................................ 133
Background ............................................................................................................ 134
Computer Based Control ..................................................................... 134
Direct Digital Control ........................................................................... 134
Advantages ............................................................................................................ 134
Lower Cost per Function ..................................................................... 134
Application Flexibility ........................................................................... 135
Coordinated Multifunction Capability ................................................... 135
Precise and Accurate Control .............................................................. 135
Reliability ............................................................................................. 135
Controller Configuration ............................................................................................................ 135
Types of Controllers ............................................................................................................ 136
Zone-Level Controller .......................................................................... 136
System-Level Controller ...................................................................... 136
Controller Software ............................................................................................................ 137
Operating Software ............................................................................. 137
Application Software............................................................................ 137
Direct Digital Control Software ........................................................ 137
Energy Management Software ....................................................... 138
Optimum Start............................................................................. 138
Optimum Stop ............................................................................. 138
Night Cycle ................................................................................. 138
Night Purge ................................................................................. 139
Enthalpy ...................................................................................... 139
Load Reset ................................................................................. 139
Zero Energy Band....................................................................... 141
Distributed Power Demand ......................................................... 142
Building Management Software ...................................................... 142
Microprocessor-Based/
DDC Fundamentals