PID Function Block
December 2009
4-91
Table 4-31. PID Function Block System Parameters Definitions (Continued)
Label
PARAMETER_NAME
DescriptionInitial ValueRange
Block
Mode
RO /
RW
Index
Number
Gain
GAIN
23 ALL greater than 0 1
Data Type: Float
The proportional gain value.
Reset
RESET
24 ALL Positive + INF
Data Type: Float
The integral action time constant. Seconds per
repeat
Balance Time
BAL_TIME
25 ALL Positive 0
Data Type: Float
The specified time, in seconds, for the internal
working value of bias to return to the operator set
bias. Also used to specify the time constant at
which the integral term will move to obtain
balance when the output is limited and the mode
is AUTO, CAS, or RCAS.
Rate
RATE
26 ALL Positive 0
Data Type: Float
The derivative action time constant, in seconds.
Back Calculation Input
BKCAL_IN
27 ALL
Status
BAD:
NC:
const
Data Type: DS-65
The analog input value and status from another
block’s BKCAL_OUT output that is used for
backward output tracking for bumpless transfer
and to pass limit status.
Value 0
Output High Limit
OUT_HI_LIM
28 ALL OUT_SCALE +/− 10% 100
Data Type: Float
Limits the maximum output value for modes other
than manual.
Output Low Limit
OUT_LO_LIM
29 ALL OUT_SCALE +/− 10% 0
Data Type: Float
Limits the minimum output value for modes other
than manual.
Back Calculation Hysteresis
BKCAL_HYS
30 ALL 0 to 50% 0.50%
Data Type: Float
The amount the output value must change away
from the its output limit before limit status is
turned off.
Back Calculation Output
BKCAL_OUT
31 RO N/A Dynamic
Data Type: DS-65
The value and status required by the BKCAL_IN
input of another block to prevent reset windup
and to provide bumpless transfer of closed loop
control.
Remote Cascade Input
RCAS_IN
32 ALL
Status
BAD:
NoCom:
NoVal:
const
Data Type: DS-65
Target setpoint and status that is provided by a
supervisory host. Used when mode is RCAS.
Value 0 Trk
Remote Out Input
ROUT_IN
33 ALL
Status
BAD:
NoCom:
NoVal:
const
Data Type: DS-65
Target output and status that is provided by a
supervisory host. Used when mode is ROUT.
Value 0 Trk
−Continued−
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