National Instruments FP-3000 - Manual (Page 95)

Appendix B Fieldbus Parameters
© National Instruments Corporation B-17 FieldPoint FP-3000 User Manual
PV_D (Process)
The process variable, or primary variable for this block. For DI and discrete
control blocks, this represents a measurement of the discrete state of the
process. For DO blocks, the process variable is the current discrete setpoint
of the block.
PV_FTIME (Scaling, Tuning)
The filter time, in seconds, used in input blocks. For analog blocks, it is the
time constant for a low pass exponential filter used to damp out rapid
oscillations in the input value before using it as the process variable. For
discrete blocks, it is the time the PV must remain constant after a change
for the change to be reported.
PV_SCALE (Scaling)
The scaling parameter used by the process variable of the block. Converts
from percent of scale to a process variable in engineering units. Contains
the same subfields as
OUT_SCALE .
PV_STATE (Process)
Index to the text describing the state of a discrete PV.
RA_FTIME (Tuning)
The filter time constant, in seconds, for the value to be used in the ratio.
RATE (Tuning)
The time constant for the derivative component of the PID block. A zero
disables the derivative term. The units are seconds.
RCAS_IN (Mode Shedding, Process)
The cascade input for a control or output block set by a remote host. This
is propagated to the setpoint of the block when it is in
RCas mode. If the
block is in RCas mode and this parameter is not updated in SHED_RCAS
time (a parameter in the resource block), the block enters mode shedding.
Mode shedding allows the block to degrade from
RCas mode into some
higher priority mode.