West Control Solutions ProVU 4 - Manual (Page 152)

ProVU4 Controller, Profiler & Recorder/Controller - Product Manual
59407, Issue 1 – March 2008 Glossary Page 151
Primary Proportional Band
The portion of the input span over which the Primary Output power level is proportional to the
process variable value. Applicable if Control Type is single or dual. For dual control a
Secondary Proportional band is used for the second output. The Control Action can be Direct
or Reverse acting.
Settings = On-Off Control or 0.5% to 999.9%
Default Value = 10%.
Also refer to: Control Action, Control Type, On-Off Control, Input Span, Overlap/Deadband,
PID, Secondary Proportional Band, and Tuning.
Process High Alarm n Value
An independent high alarm value parameter is available for each alarm that is set as Process
High type. It defines the process variable value above which Alarm n will be active.
Settings = Scale Range Upper to Lower Limit
Default Value = Scale Range Upper Limit.
Also refer to: Alarm Operation, Alarm Types, Process Variable, Scale Range Lower Limit and
Scale Range Upper Limit.
Process Input
The main input used to monitor the value process to be controlled. This is known as the
Process Variable or PV. The input circuit is a “Universal” type, supporting all common
thermocouples and RTDs as well as DC linear mV, voltage or mA signals suitable for almost
any parameter that can be converted into a electronic signal. Linear signals can be scaled
into engineering units using the Scale Range Lower Limit and Scale Range Upper Limit
parameters.
Also refer to: Auxiliary Inputs, Input Span, PV Offset, Process Variable , Scale Range Lower
Limit and Scale Range Upper Limit.
Process Low Alarm n Value
An independent low alarm value parameter is available for each alarm that is set as Process
Low type. It defines the process variable value below which Alarm n will be active.
Settings = Scale Range Upper to Lower Limit
Default Value = Scale Range Lower Limit.
Also refer to: Alarm Operation, Alarm Types, Process Variable, Scale Range Lower Limit and
Scale Range Upper Limit.
Process Variable (PV)
Process Variable is the parameter that is to be controlled to the actual setpoint value. It is
monitored by the main process input of the instrument, and can be any type that can be
measured by that circuit. Common types are Thermocouple or RTD temperature probes, or
pressure, level, flow etc from transducers that convert these parameters into DC linear input
signals (e.g. 4 to 20mA). Linear signals can be scaled into engineering units using the Scale
Range Lower Limit and Scale Range Upper Limit parameters.
Also refer to: Actual Setpoint, Engineering Units, Input Span, Linear Input, Process Input,
RTD, Scale Range Lower Limit, Scale Range Upper Limit and Thermocouple.