Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller FLEXIBLE CONTROL STRATEGIES - Manual (Page 29)

2.7.15 PROPORTIONAL INTEGRAL DERIVATIVE 0
The Proportional Integral Derivative 0 (PID 0) module (which is part of the CON module) performs
an interactive PID calculation that duplicates the behavior of conventional analog controllers. Ca-
pabilities include external reset, additive feedforward, anti-reset windup, support of all control
modes (e.g., P, PI, PD, PID, etc.), and bumpless-balanceless auto transfer. The Control Output
(CO) is determined by the equation
CO
=
PN
+
RN
+
FF
where: PN
=
[ ∂
PV
∂
t
+
DV
]
100
Pb
when CTC = 1: RN
=
Tr
∫
(
RF
−
FF
−
RN
) ∂
t
0
T
when CTC = 0: RN
=
RF
−
PN
−
FF
When CTC = 0, the output = the Reset Feedback (RF) value. When CTC = 1, the output responds
with integral action based on the value of RF.
When reset time is set to 0.0, the output is calculated as follows: CO = PN + FF + MR to allow bi-
asing of the output signal with Manual Reset.
The final value of CO is limited between the output limits specified. When limited, the integral term
is adjusted to prevent reset windup.
For standard control applications, Reset Feedback (RF) should always be connected to the output
of the Auto/Manual Selector module and Control Track Common (CTC) should always be con-
nected to the Auto status output of the Auto/Manual Selector module. In this way the transfer from
manual to automatic operatic operation does not produce a process bump when the setpoint and
process are mismatched at the time of transfer. If Reset Feedback is being used as an external re-
set or for other purposes, proper operation of this module requires that it be a 0 - 100 value.
The tables that follow list the input variables and the parameters. An illustration of the PID 0 mod-
ule follows the tables.
Inputs Inputs
WIRELIST SYMBOL DATA
TYPE
ASSIGNED VALUE WIRELIST SYMBOL DATA
TYPE
ASSIGNED VALUE
B154 DV0 C B156 CTC0 L
B155 FF0 C B157 RF0 C
Output Datapoint: C123
Parameters Parameters
SYMBOL DATAPOINT ASSIGNED VALUE SYMBOL DATAPOINT ASSIGNED VALUE
OH0 C109 TD0 C108
OL0 C110 MR0 C111
IR0 C115 RSW0 L106
PB0 C106 PV0 C100
TR0 C107
PN ... Proportional and Derivative value,
RN ... Reset value
FF ... Feedforward,
MR ... Manual Reset
PV ... Process Variable
DV ... Deviation
Pb ... Proportional Band
Tr ... Reset Time
CO ... Control Output
CTC ... Control Track Command
RF ... Reset Feedback.
FCS 53MC5000 Flexible Control Strategies
2-22
PID-0