WEST P4100 - Process High Alarm 2 Value; Process Low Alarm 1 Value; Process Low Alarm 2 Value; Process Variable (PV)

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- DIN Controllers & Indicators - Product Manual
59305, Issue 5 – March 2005 Glossary Page 121
Process High Alarm 2 Value Type: General Parameter
This parameter, applicable only when Alarm 2 is selected to be a Process High alarm. It is
similar to the Process High Alarm 1 Value.
Display code = -)53, Default value = Scale Range Upper Limit.
Also refer to Alarm Operation, Process High Alarm 1 Value, Process Variable, Scale Range
Lower Limit and Scale Range Upper Limit.
Process Low Alarm 1 Value Type: General Parameter
This parameter, applicable only when Alarm 1 is selected to be a Process low alarm, defines
the process variable value below which Alarm 1 will be active. Its value may be adjusted
between Scale Range Upper Limit and Scale Range Lower Limit.
Display code = -+52, Default value = Scale Range Lower Limit.
Also refer to Alarm Operation, Process Low Alarm 2 Value, Process Variable, Scale Range
Lower Limit and Scale Range Upper Limit.
Process Low Alarm 2 Value
Type: General Parameter
This parameter, applicable only when Alarm 2 is selected to be a Process low alarm. It is
similar to the Process Low Alarm 1 Value.
Display code =
-+53, default value = Scale Range Lower Limit.
Also refer to Alarm Operation, Process Low Alarm 1 Value, Process Variable, Scale Range
Lower Limit and Scale Range Upper Limit.
Process Variable (PV) Type: General Definition
Process Variable is the variable to be measured by the primary input of the instrument. The
PV can be any parameter that can be converted into a electronic signal suitable for the input.
Common types are Thermocouple or PT100 temperature probes, or pressure, level, flow etc
from transducers which convert these parameters into linear DC 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 Input Span, Offset, Scale Range Lower Limit and Scale Range Upper Limit.
Process Variable Offset
Type: General Parameter
- Refer to Offset.
Rate (Derivative)
Type: Controller Tuning Parameter
Rate is adjustable in the range 0 seconds (OFF) to 99 minutes 59 seconds. It defines how
the control action responds to the rate of change in the process variable. This parameter
should not be used in modulating value applications as it can cause premature wear due to
constant small adjustments to the valve position. The Rate parameter is not available if
primary control output is set to On-Off.
Display code = 95#., default value = 1.15.
Also refer to On-Off Control, PID, Process Variable and Tuning.