PID Function. Schneider Electric Software PLC Application-Specific Functions, Micro/Junior/Pro, 4.5
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Description of the regulation functions
PID Function
General
Available functions
The PID function completes a PID correction via an analog measurement and setpoint on the [0-10000] format and provides an analog command to the same format.
The PID OF is composed of the following functions: l l l l l l l l l serial / parallel PID algorithm, forward / backward action (according to the KP gain sign), action derived from measurement or from distance, high and low limitation of the setpoint to [0-10000], high and low limitation of the output in automatic mode, anti-saturation of the integral action,
Manual/Automatic operating modes without definitely changing,
PID access control through the dialog operator, operating in integrator for (KP = TD =0).
l l
Note:
The display parameters used by the CCX 17 are shown in physical units,
For a correct PID operation, you must stay within the scale of [0-1000] for the measurement and the setpoint.
TLX DS 37 PL7 xxE
359
Description of the regulation functions
Operating principles
The following diagram presents the operating principle of the PID function.
TS
CORRECTOR P.I.D
.
TI
The Setpoint branch
INTERNAL
SETPOINT
SET POINT
S.P
INTERNAL
MEASUREM
PROCESS
VALUE
P.V
10000
Limiter
0
Deviation Integrated
+
SETPOINT
USED
-
MEASUREMENT
USED
ε
0
1
Derivative action
Action derived on the measurement
PV_DEV
TD
d
dt
Derived
+
The PID action
The Measurement branch
+
+
KP
OUT_MAX
Limiter
OUT_MIN
The PID operation modes
1
AUTO
0
OUTP
OUT_MAN
Followed without repeated command attempts on Auto – Manu >switching
DIALOGUE OPERATOR CCX 17
- PV_MMI - PV_SUP
- SP_MMI - PV_INF
Note: The description of the parameters used is presented in the (See Programming
the PID function, p. 361) module.
360
TLX DS 37 PL7 xxE
Preuzimanje
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