Technical information

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Modicon M340 automation
platform
0
Programmable process control
Unity Pro software
Process control in machines
Unity Pro contains CONT_CTL, a library of 36 function blocks used to create control
loops for machine control.
All requirements for closed loop control functions in machines are adequately met by
Modicon M340 thanks to the wealth of functions in the library and the flexibility with
which function blocks can be linked together through programming. This solution
therefore eliminates the need for external controllers and simplifies the overall
control architecture of the machine, as well as its design, roll-out and operation.
The function blocks, EF or EFB, can be used in all Unity Pro languages i.e. LD, ST, IL
and FBD. FBD is particularly suitable for accessing control processing operations in
Unity Pro through its assistant for entering and viewing parameters and function
block variables.
CONT_CTL library functions
The library consists of five function families:
Input data conditioning
Controllers
Mathematical functions
Measurement processing
Output value processing
Input data conditioning
DTIME
Pure delay time
INTEGRATOR
Integrator with limiting
LAG_FILTER
First order time lag
LDLG
Lead/lag function with smoothing
LEAD
Lead function with smoothing
MFLOW
Mass flow calculation based on the measurement of differential
pressure or flow speed with pressure and temperature
compensation
QDTIME
Dead time term
SCALING
Scaling
TOTALIZER
Integrator (typically of flow) until a limit (typically a volume) is
reached, with automatic reset
VEL_LIM
Velocity limiter, with manipulated variable limiting
Controllers
PI_B Basic PI controller: PI algorithm with a mixed structure
(series/parallel)
PIDFF Complete PID controller: PID algorithm with a parallel or mixed
structure (series/parallel)
AUTOTUNE Automatic tuner setting for the PIDFF (complete PID) controller or
the PI_B (basic PI) controller
Identification using Ziegler Nichols type method
Modelling based on first order process
Building of control parameters with criterion for prioritizing
either the reaction time to disturbance (dynamic) or the stability of
the process
v
v
v
IMC Model-based controller The model is a first order model with delay.
This controller is useful:
When there are serious delays compared with the main time
constant of the process; this scenario cannot be satisfactorily
resolved by standard PID process control
For regulating a non-linear process IMC can handle any stable
and aperiodic process of any order
v
v
SAMPLETM Control of controller startup and sampling
STEP2 Simple two-position controller
STEP3 Three-position controller for temperature regulation
Mathematical functions
COMP_DB Comparison of two values, with dead zone and hysteresis
K_SQRT Square root, with weighting and threshold, useful for linearization
of flow measurements
MULDIV_W Weighted multiplication/division of 3 numerical values
SUM_W Weighted summation of 3 numerical values
b
b
b
b
b
AUTOTUNE
PV
SP
RCPY
START
PREV
PARA
TR_I
TR_S
PV_O
SP_O
PARA_C
TRI
TRS
INFO
STATUS
TT18_PV
TT18_SP
TC18_OUT
TC18_START
TC18_PREV
TC_PARA
TC18_PARA
TC18_OUT
1
TC2_OUT
TC2_OUT
TC18_OUT
PV
SP
PARA
TR_I
TR_S
PIDFF
FF
RCPY
MAN_AUTO
OUT OUT
OUTD
MA_O
INFO
STATUT
TC2_OUT
MS
TC18_OUT
IN
PARA
TR_I
TR_S
FORC
MA_FORC
MAN_AUTO
OUT OUT
OUTD
MA_O
STATUT
Example: PID controller with MS manual control
AUTOTUNE
PV
SP
RCPY
START
PREV
PARA
TR_I
TR_S
PV_O
SP_O
PARA_C
TRI
TRS
INFO
STATUS
TT18_PV
TT18_SP
TC18_OUT
TC18_START
TC18_PREV
TC_PARA
TC18_PARA
TC18_OUT
1
TC2_OUT
TC2_OUT
TC18_OUT
PV
SP
PARA
TR_I
TR_S
PIDFF
FF
RCPY
MAN_AUTO
OUT OUT
OUTD
MA_O
INFO
STATUT
TC2_OUT
MS
TC18_OUT
IN
PARA
TR_I
TR_S
FORC
MA_FORC
MAN_AUTO
OUT OUT
OUTD
MA_O
STATUT
Example: PID controller with MS manual control
Presentation,
functions
CONT_CTL, programmable process control integrated in
Unity Pro
Processors:
page 1/2
Communication:
page 3/2
Software:
page 4/2
Ruggedized Modicon M340 modules:
page 6/2
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