West Control Solutions N6600 - Manual (Page 21)

3.2.1 Input Filter Time Constant
The Controller input is equipped with a digital filter which is used to filter out any
extraneous impulses on the process variable. This filtered PV is used for all
PV-dependent functions (control, alarms etc.). The time constant for this filter may
be adjusted in the range 0.0 seconds (filter OFF) to 100.0 seconds in 0.5 second
increments. The default setting is 2.0 seconds.
CAUTION: If this parameter is set to an excessively high value, the control
quality may be significantly impaired. The value chosen should be
sufficiently large to attenuate stray noise on the process variable signal but
no larger.
3.2.2 Process Variable Offset
This parameter is used to modify the actual process variable value (measured at
the Controller’s input terminals) in the following manner:
Offset PV value = Actual PV value + Process Variable Offset value.
O075-3 3-5
PM-0075
NOTES ON TABLE 3-1
1. These parameters are not operative if the Proportional Band = 0.
2. Switching differential with ON/OFF Control Output.
3. These parameters are optional; only one legend will appear for each alarm.
4. Only applicable if Output 2 is fitted.
5. Appears only if ramp rate
rp
is not switched OFF.
6. Applicable only if the Communications Option PCB is fitted.
7. Does not appear in Operator Mode unless
rPEN
= 1.
8. For Single Setpoint operation, the legend displayed is
SP
; for Dual Setpoint
operation, the legend displayed is
SP1
.
9. Applicable only when Heater Break Alarm Strategy is configured to Percentage
Mode.
10. Does not appear if Heater Break Input Type is configured to be SCRi.