National Instruments NI-FBUS - Manual (Page 92)

Chapter 4 Parameters
© National Instruments Corporation 4-27 NI-FBUS Configurator User Manual
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.
RCAS_IN_D (Mode Shedding, Process)
The discrete 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.