DCP200 Profile Controller & Recorder -Product Manual
Page 132 Glossary 51-52-25-150, Issue 1 –April 2009
15 Appendix 1 –Glossary of Terms Used
Active Setpoint
The term Active Setpoint is used to describe the currently selected setpoint when the
instrument is in Controller Mode. Controllers can use Local Setpoint 1 and/or the Alternative
Setpoint. Only one of the setpoints can be active at any time. During Profiler Control, the
setpoint value is controlled by the profiler function.
Also refer to: Actual Setpoint, Alternative Setpoint, Controller Mode, Local Setpoints, Profiler
Mode, Remote Setpoint, Setpoint, and Setpoint Selection.
Actual Setpoint
Actual Setpoint is the effective current value of the active setpoint. This will be different to the
Active Setpoint’s target value if the setpoint is ramping. The actual setpoint will rise or fall at
the ramp-rate set, until it reaches its target setpoint value. During Profiler Control, the Actual
Setpoint value is controlled by the profiler function.
Also refer to: Active Setpoint, Controller Mode, Profiler Mode, Setpoint, Setpoint Ramp Rate
and Setpoint Selection.
Alarm Configuration
A sub-menu of Configuration Mode used to adjust the alarm parameters. (Alarm types,
values, hysteresis and inhibiting).
Also refer to: Alarm Hysteresis, Alarm Inhibit, Alarm Operation, Alarm Types and
Configuration Mode.
Alarm Hysteresis
An adjustable band through which the process variable must pass before the alarm will
change state. This Hysteresis is only applicable to alarms based on the Process Value or
Control Deviation, as illustrated below. The band is always on the “safe” side of an alarm
point, e.g. a high alarm’s hysteresis band is below the high alarm value, and a low alarm’s
hysteresis is above the low alarm value. Rate Of Change Alarms have a different type of
hysteresis based on the length of time the rate is above the threshold.
Settings = 1 LSD to full span from the setpoint.Default value = 1 LSD.
Refer to the Alarm Hysteresis Operation diagram on the next page.
Also refer to: Alarm Types, Loop Alarm, Alarm Operation, LSD, Minimum Duration Of
Change, Process Variable, and Rate Of Change Alarm.