Siemens 125-1957 - Manual (Page 43)

Siemens Building Technologies, Inc. 33
Glossary
Overview
The glossary contains terms and acronyms that are used in this manual. For definitions of
point database descriptors, see Chapter 3, Point Database. For definitions of commonly used
terms as well as acronyms and abbreviations associated with the APOGEE Automation
System, see the Siemens Building Technologies Technical Glossary of Building Controls
Terminology and Acronyms, (125-2185). This book is available from your local Siemens
Building Technologies representative.
Al
Analog Input. Physical point which accepts a continuous variable signal.
algorithm
Mathematical formula used to calculate an output value using varying inputs.
AO
Analog Output. Physical point that generates a continuous variable signal.
centralized control
Type of control offered by a controller that is connected, by means of a Floor Level Network
(FLN), with an APOGEE field panel.
control loop
Proportional Integral Derivative (PlD) algorithm that is used to control an output based on a
setpoint and an input reading from a sensor.
DDC
Direct Digital Control.
Dl
Digital Input. Physical output point that accepts a two-state signal (that is, ON/OFF,
OPEN/CLOSED, YES/NO, etc.).