Despatch P1400+ Temperature Controller - Manual (Page 90)

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Primary Proportional Band Type: Controller Tuning Parameter
The portion of the input span over which the Primary Output power level is proportional to the
process variable value. It may be adjusted in the range 0.0% (ON/OFF) to 999.9%.
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.
The Display value =
Pb_P , default value = 5.0%.
Also refer to Control Action , Control Type , On-Off Control , Input Span , Overlap/Deadband , PID ,
Secondary Proportional Band , and Tuning .
Process High Alarm 1 Value Type: General Parameter
This parameter, applicable only when Alarm 1 is selected to be a Process High alarm, defines the
process variable value above which Alarm 1 will be active. Its value may be adjusted between Scale
Range Upper Limit and Scale Range Lower Limit.
Display code =
PHA1 , Default value = Scale Range Upper Limit.
Also refer to Alarm Operation , Process High Alarm 2 Value , Process Variable , Scale Range
Lower Limit and Scale Range Upper Limit .
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 =
PHA2, 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 =
PLA1 , 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 =
PLA2 , 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 .