User's Manual

DCP200 Profile Controller & Recorder - Product Manual
51-52-25-150, Issue 1 – April 2009 Glossary Page 143
Input Range
This is the overall process variable input range and type as selected by the Process Input
Type parameter. This range can be scaled by the Scale Range Upper & Lower Limits.
Also refer to: Input Span, Process Input, Scale Range Lower Limit and Scale Range Upper
Limit.
Input Span
The measuring and display limits, as defined by the Scale Range Lower and Scale Range
Upper Limits. The trimmed span value is also used as the basis for calculations that relate to
the span of the instrument (e.g. proportional bands).
Settings = 100 LSD’s to the full Input Range. Default value = Input Range
Also refer to: Input Range, LSD, Primary Proportional Band, Scale Range Lower Limit, Scale
Range Upper Limit and Secondary Proportional Band.
Integral Time Constant
Integral action biases proportional control output(s) to compensate for process load
variations, until the control deviation value is zero. Integral Time Constant is also known as
“Automatic Reset”. Decreasing the time constant increases the Integral action. This
parameter is not available if the primary output is set to On-Off.
Settings = 1 sec to 99 min 59 sec and OFF. Default value = 05:00
Also refer to: Control Deviation, On-Off Control, PI Control, PID, Primary Proportional Band,
Secondary Proportional Band, Derivative Action, and Tuning.
Latching Relay
A type of relay that, once it becomes active, requires a reset signal before it will deactivate. If
latching relays are required, they can be fitted externally as slaves to the internal (non-
latching) relays of this instrument.
Also refer to: Relay
LED
Light Emitting Diode. LED’s are used as indicator lights (e.g. for the alarm indication,
automatic tuning stats and manual mode).
Also refer to: Alarm Operation, Alarm Types, Automatic Tuning and Manual Mode.
Linear Input
A mVDC, mADC or voltage signal used to represent the value of the process variable. This
can be any variable that can be converted into a suitable DC linear signal. Common
examples are Humitity, pressure, pH or temperature.
Auxiliary linear inputs can also be installed, these can be used to provide a remote setpoint.
Also refer to: Auxiliary Input, Input Range, Linear Output, mVDC, mADC, Process Variable,
Remote Setpoint and VDC.