Red Lion PAXDP User Manual
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CALCULATION ROUNDING*
Rounding selections other than one, cause the Calculation Display to ‘round’ to
the nearest rounding increment selected (ie. rounding of ‘0.005’ causes 0.121 to
round to 0.120 and 0.124 to round to 125). Rounding starts at the least significant
digit of the Calculation Display. Remaining parameter entries (scaling point
values, setpoint values, etc.) are not automatically adjusted to this display rounding
selection. The displayed decimal point reflects that programmed in
.
CALCULATION FILTER SETTING
to
The calculation filter setting is a time constant expressed in tenths of a
second. The filter settles to 99% of the final display value within approximately
3 time constants. This is an Adaptive Digital Filter which is designed to steady
the Calculation Display reading. A value of ‘0’ disables filtering.
CALCULATION FILTER BAND*
The digital filter will adapt to variations in the calculation filter. When the
variation exceeds the calculation filter band value, the digital filter disengages.
When the variation becomes less than the band value, the filter engages again.
This allows for a stable readout, but permits the display to settle rapidly after a
large process change. The value of the band is in display units, independent of
the Display Decimal Point position. A band setting of ‘0’ keeps the digital filter
permanently engaged.
to
display units
*
The decimal point position is dependent on the selection made in the
“Display Decimal Point” parameter.
to
CALCULATION CONSTANT VALUE
The constant value is used in the Calculation Function formulas to provide
offsetting or scaling capabilities. For the
,
, and
calculation functions, the Constant decimal point matches that Calculation
Decimal point position. For these functions, the “Constant Value” must be
lowered to a value of 0 for no offset.
For the
,
, and
()
calculation functions, there is no
“Constant Value” decimal point shown. However, when Input A “Display
Decimal Point”, Input B “Display Decimal Point” and “Calculation Decimal
Point” are in the same position, then the “Constant Value” decimal point will be
assumed to be at the same location as the “Calculation Decimal Point”. For the
Calculation Display to have the same resolution as Inputs A & B, the “Constant
Value” must be a value of 1 with trailing 0's for each assumed decimal point
location. Example: With Input A, Input B and the Calculation decimal points
entered as 0.00, then the “Constant Value” would be entered as 100 for no gain.