Emerson Rosemount OCX 8800, Instruction Manual

Page: 158 / 306

Section 7: Foundation
Fieldbus
April 2017
Instruction Manual
IM-106-880C, OI
13
2
Proportional/ Integral/Derivative (PID) Function
Block
Parameter
Index
Number
Units Description
LO_PRI 52 None The priority of the LO alarm.
MATH_FORM 73 None Selects equation form (series or standard).
MODE_BLK 05 None The actual, target, permitted, and normal modes of the block.
Target: The mode to “go to”
Actual: The mode the “block is currently in”
Permitted: Allowed modes that target may take on
Normal: Most common mode for target
OUT 09 EU of OUT SCALE The block input value and status.
OUT_HI_LIM 28 EU of OUT_SCALE The maximum output value allowed.
OUT-LO_LIM 29 EU of OUT_SCALE The minimum output value allowed.
OUT_SCALE 11 None The high and low scale values, engineering units code, and number of
digits to the right of the decimal point associated with OUT.
PV 07 EU of PV_SCALE The process variable used in block execution.
PV_FTIME 16 Seconds The time constant of the first-order PV filter. It is the time required for a
63 percent change in the IN value.
PV_SCALE 10 None The high and low scale values, engineering units code, and number of
digits to the right of the decimal point associated with PV.
RATE 26 Seconds The derivative action time constant.
RCAS_IN 32 EU of PV_SCALE Target setpoint and status that is provided by a supervisory host. Used
when mode is RCAS.
RCAS_OUT 35 EU of PV_SCALE Block setpoint and status after ramping, filtering, and limiting that is
provided to a supervisory host for back calculation to allow action to be
taken under limiting conditions or mode change. Used when mode is
RCAS.
RESET 24 Seconds per repeat The integral action time constant.
ROUT_IN 33 EU of OUT_SCALE Target output and status that is provided by a supervisory host. Used
when mode is ROUT.
ROUT_OUT 36 EU of OUT_SCALE Block output that is provided to a supervisory host for a back calcula-
tion to allow action to be taken under limiting conditions or mode
change. Used when mode is RCAS.
SHED_OPT 34 None Defines action to be taken on remote control device time-out.
SP 08 EU of PV_SCALE The target block setpoint value. It is the result of setpoint limiting and
setpoint rate of change limiting.
SP_FTIME 69 Seconds The time constant of the first-order SP filter. It is the time required for a
63 percent change in the IN value.
SP_HI_LIM 21 EU of PV_SCALE The highest SP value allowed.
SP_LO_LIM 22 EU of PV_SCALE The lowest SP value allowed.
SP_RATE_DN 19 EU of PV_SCALE per
second
SP-RATE_UP 20 EU of PV_SCALE per
second
Ramp rate for downward SP changes. When the ramp rate is set to zero,
the SP is used immediately.
Ramp rate for upward SP changes. When the ramp rate is set to zero,
the SP is used immediately.
SP_WORK 68 EU of PV_SCALE The working setpoint of the block after limiting and filtering is applied.
STATUS_OPTS 14 None Allows you to select options for status handling and processing. The
supported status option for the PID block is Target to Manual if Bad IN.
STRATEGY 03 None The strategy field can be used to identify grouping of blocks. This data
is not checked or processed by the block.