3-4 PV Shift
3-4 PV Shift
In certain application it is desirable to shift the indicated
value from its actual value. This can be easily accomplished
with this unit by using the PV shift function.
Cycle the unit to the SHIF parameter by using the scroll key.
The number you adjust here, either positive or negative, will
be added to the actual value. The SHIF function will alter PV
alter PV
SHIF: PV shift (input correction) value
SHIF:
3-5 Digital Filter
3-5 Digital Filter
In certain applications the process value is too unstable to be
read. To Improve this a programmable low pass filter incorporated
in the L91 can be used. This is a first order filter with time constant
specified by FILT parameter which is contained in setup menu. The
FILT is defaulted to 0.5 sec. before shipping. Adjust FILT to change
the time constant from 0 to 60 seconds. 0 second represents no
filter is applied to the input signal. The filter is characterized by the
following diagram.
35
PV
Time
FILT=0
1sec
FILT=1
FILT=30
1sec
Figure 3-2 Filter Characteristics
Figure 3-2 Filter Characteristics
UM L91-Rev 8
