Loop Control With SIMATIC

SIMATIC based technologyLoop control with SIMATIC

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Contents of the Product Brief “Closed-loop control with SIMATIC”

Selection guide for controllers Page 3

Controller types Page 4

Control structures Page 5

Integrated functions PID Control in STEP 7®, STEP 7 (Micro/Win), CFC, CPU 313C/314C:Integrated, simple PID control algorithm for universal applications with SIMATIC S7

Page 12

PID Temperature Control:Integrated, simple PID control algorithm designed specifically for temperature control

STEP 7 option package (PID control)

Modular PID Control:Range of function blocks for modular closed-loop control for S7-300/S7-400

Page 9

Standard PID Control:PID controller with off-the-shelf control structures for SIMATIC S7-300/S7-400

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Function modules FM 355 C/S, FM 455 C/S: Controller module with backup facility for universal applications with online self-tuning for SIMATIC S7-300, C7, ET 200M

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FM 355-2 C/S:Controller module with backup facility for temperature control and integrated online self-tuning for SIMATIC S7-300, C7, ET 200M

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Application modules Complex closed-loop control with the FM 458 application module in SIMATIC S7-400

Product Brief “FM 458” (can be ordered using the fax form on the back page)

STEP 7 option package (PID self-tuner)

PID Self-Tuner: Function block for online self-optimization of PID controllers for SIMATIC S7-300/S7-400, FM 355/FM 455

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Pulse width modulation ET 200S function modules:2 Pulse module for intelligent control of actuators

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Technical specifications Summary of closed-loop control functions/modules Page 14

Summary

The tasks to be handled by program-mable controllers (PLC) are becoming increasingly complex. In many cases, solutions for closed-loop control tasks already belong to the standard reper-toire of a PLC.

Closed-loop control is required in many different fields of application:

· General mechanical engineering

· Industrial plant construction

· Industrial furnaces cooling and heating unit construction

· Food processing industry

· Rubber and plastics machines

· Wood and paper industry

· Chemical and process industry

· Glass and ceramics industry

The most frequent applications are PID controls for analog variables such as temperature, pressure and flow. SIMATIC® provides many functions for solving such closed-loop control tasks:

· Integrated functions are available in the programming software or in the CPU for simple closed-loop control tasks.

· Appropriate option packages based on the STEP® 7 programming software are available for solving medium and complex control tasks.

· Highly complex closed-loop control tasks with backup facilities are most appropriately solved using special function groups.

Control with SIMATIC offers many advantages:

· SIMATIC offers a system-wide product range for control tasks of any complexity

· The software solutions can be implemented with all SIMATIC S7-200®, S7-300®, S7-400® and C7 controllers as well as with PC-based control (WinAC®)

· The hardware solutions can be used in the SIMATIC S7-300/S7-400 and C7 controllers and distributed with the ET 200®

· Each solution can be implemented system-wide via all controllers with similar functions

· All functions are parameterized in the same way using a simple screen form interface

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Task Can be used in all types of temperature, volumetric flow, level, and pressure control

Requirements Basic Intermediate Advanced

Instances SW SW SW HW module

Products PID Control StandardPID Control

ModularPID Control

FM 355C, FM 355S, FM 455C, FM 455S

Formats Suitable for flexible use in SIMATIC S7-300, S7-400, C7, ET 200

Controllers Continuous closed-loop controllers, step controllers, pulse controllers

Functions · Closed-loop control basic functions

· Wide range of closed-loop control functions

· Extensive range of closed-loop control functions

· Backup facility: continuation of closed-loop control in the event of a stop or CPU failure

User-friendly online self-optimization for all controllers with PID self-tuner

Blocks FB 41FB 42FB 43, etc.

FB 1FB 2FC 1

27 standardfunction blocks

C controllers: FM 355C/455CS controllers: FM 355S/455SPulse controllers: FM 355S/455S

Closed-loop control structures

Preset; closed-loop control structures and processing functions can be adapted through parameter assignment

Freely configurable: the function blocks can be combined and interconnected as required

Preset; closed-loop control structures and processing functions can be adapted through parameter assignment

Configuration tools Tabular parameter overview

Graphic configuration with user-friendly parameter assignment screen formsChanges applied and recorded immediately in online operation

Task Designed specifically for temperature control

Requirements Basic Intermediate to advanced

Instances SW HW module

Products PID temperature control

FM 355-2

Formats Suitable for flexible use in SIMATIC S7-300, S7-400, ET 200M, C7

SIMATIC S7-300, C7, ET 200M

Controllers Continuous closed-loop controllers, step controllers, pulse controllers

Functions -- · Specialist temperature algorithms

· Integrated online self-optimization

· Self-optimization as initial/follow-up optimization at operating point

· Backup facility

· Ideal support for thermocouples

Blocks FB 58, FB 59 Function blocks for integration into the user program


· Closed-loop control basic functions

· Initial optimiz. and adaptation to operating point

Preset; closed-loop control structures and processing functions can be adapted via parameter assignment

Configuration tools Tabular parameter overview

Graphic configuration with user-friendly parameter assignment screen formsChanges effective and recorded immediately in online operation

Selection guide for control products

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Controller types

We would like to start with a summary of the most important controller types and structures that can be implemented with SIMATIC S7/C7.

Controller typesThe choice of controller depends on the final control element to be controlled. All closed-loop control products offer the following controller types:

Continuous controllersIn continuous controllers (see Fig. 1a), the manipulated variable Y can assume any value within the control range. The output value is an analog value. Such controllers are required if the final control element requires a continuous signal (e.g. a voltage constantly applied to a valve).

Pulse controllersIn pulse controllers (see Fig. 1b), the continuous output signal is converted into a mark/space signal. The control response is determined by the ratio between the pulse length and the intermediate spaces.

In the case of a temperature control with electrical heating elements, for example, a specific mark/space ratio is output for each constant temperature value. The pulse controller may have a two-position or three-position response (e.g. HEATING - OFF - COOLING).

Step controllersA step controller (see Fig. 2) has 3 switching states, e.g. COUNTERCLOCKWISE - STOP - CLOCKWISE. Step controllers are used if a control element with latching is to be controlled. These final control elements must always have an integrated-action response. They can be implemented with or without a position feedback.

Step controllers are used, for example, for electric motors as the actuator, for valves, dampers, slides etc. The motor only receives a corresponding pulse when either the actual value deviates from the setpoint (without position feedback) or when the position feedback deviates from the calculated manipulated variable.

Fig. 1 Response of a continuous controller (a) and a pulse controller (b)

Fig 2: Response of a step controller for a valve

a) Continuous controller:Response of manipulated variable

b) Pulse controller with one digitaloutput (2-position control):

Response of pulse/space signal: A short period T, i.e. many posi-tioning pulses per unit of time, result in an almost continuous response of the manipulated variable

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1. Digital output (DO):Positioning pulse for Open valve

2. Digital output (DO):Positioning pulse for Close valve

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Control structures

PID 1Master controller

PID 2Follow-upcontroller

Liquid

Manipul. variable

Heatexchanger

Temperature

Flow

Temperature/flow cascade control

Temperature control with classical ratio cascade control

PID 1Mastercontroller

PID 2Follow-upcontroller

Manipul. variable

Ratio factor

Flow of gas

Air

Gas

Flow of air

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Fixed setpoint controlThis is the simplest control structure where a fixed setpoint is defined on the controller. This setpoint is only rarely changed depending on the process.

A fixed setpoint controller is frequently used as a single-loop controller, and also as a master controller in a cascade, ratio or blending control.

Follow-up controlIn contrast to a fixed setpoint control, the setpoint is changed online here. The special task of the follow-up controller is to bring the controlled variable into line with the continuously modified setpoint quickly and precisely. A follow-up controller is frequently used as a subordinate controller in a cascade structure.

Cascade controlIf the control results are unsatisfactory when using single-loop control, the control response can be improved by using additional variables from the process.

A cascade control structure comprising a master controller and a follow-up controller, is illustrated in the upper figure.

The measured intermediate variable is adjusted to a defined setpoint by the follow-up controller. This setpoint is defined by the master controller and its result.

Examples

· Heater with control of steam flow and temperature

· Position control with subordinate speed and current controls.

Ratio controlIn some processes, the ratio between two or more controlled variables is more important than their absolute values. Such tasks require a ratio control.

The subordinate control loop in the lower figure shows the design of a ratio control where the ratio of air and gas is held constant.

A combination of a cascade structure and a subordinate ratio structure results in a ratio cascade control as shown in the lower figure using an example of a temperature control (master controller) with a ratio control for air and gas (follow-up controller).

Blending controlIn blending control, the components to be mixed must be held at a defined percentage similar to the ratio control. The total quantity required must also be controlled.

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The FM 355 (right) and FM 455 (left) closed-loop control modules

The FM 355 closed-loop control modules for SIMATIC S7-300, C7 and ET 200M (on S7-300/S7-400 master) and FM 455 for S7-400 can also be used in PCS 7 and offer the same functionality.

The only difference is the number of channels: the FM 355 has 4 channels, the FM 455 has 16.

Both modules have a special self-optimization function with which the controllers can be optimized. The backup functions enable fault-free operation if the CPU fails or goes to Stop.

Two versions of the modules are available for driving different final control elements:

· FM 355 C/FM 455 C as a continuous controller for driving analog final control elements.

· FM 355 S/FM 455 S as a step or pulse controller for driving motorized final control elements (integrating control elements or binary-driven final control elements e.g. electrical heating strips and cartridges).

ApplicationThe closed-loop control modules are suitable for universal use, e.g. for temperature, pressure, volumetric flow or level control in numerous applications in machine and system production.

The backup function in particular makes the modules particularly suitable for I&C applications in the chemical, glass and ceramics industries. They can also be used to control continuous processes and batch processes.

Scope of deliveryThe closed-loop control modules contain several ready-to-use control structures:

· Fixed setpoint control

· Cascade control

· Ratio control

· 3-component control

Up to 4 controllers can be interconnect-ed to form one control structure (this limit also applies to FM 455).

The parameter assignment software supplied with the modules contains extensive online help for the input screen forms as well as a function block that provides the module data to the STEP 7 program in the CPU channel-by-channel. A comprehensive manual and Getting Started tutorial are also provided.

Functions

Controller optimizationThe module has two individual algorithms with various optimization options:

· Fuzzy controller with integrated online self-optimization for temperature ranges. Optimization possible for setpoint step changes of 12% and upwards.

· PID controller can be optimized via the parameter software (PG/PC required).

Backup modeThis function ensures that the controller continues to operate even if the CPU fails or goes to Stop.

It is possible to set a safety setpoint or a safety manipulated variable for backup mode.

Operating modesIn addition to automatic and backup modes, the modules also work in the following modes:

· Manual mode

· Follow-up mode

· Safety mode

Firmware updateIn order to update the firmware fast and effortlessly, simply download the current version from the Internet. Use the parameter assignment software to transfer the new firmware into the module.

Test functionsExtensive test functions and simulation options are available to offer assistance during the startup process.

FM 355 and FM 455universal closed-loop control modules

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FM 355 and FM 455 universal closed-loop control modules

DesignBoth modules are double-width. Sensors and actuators can be connected directly to the module.

InputsThe 4 or 16 analog inputs can be used for analog-value acquisition or for disturbance variable feedforward. An additional input is used for temperature compensation in thermocouple mode.

The resolution is 12 or 14 bits including the sign.

The sampling time comprises:

· 12-bit resolution: 20 ms * no. of channels + 20 ms for temperature compensation

· 14-bit resolution: 100 ms * no. of channels + 100 ms for temperature compensation

On the FM 455, sampling takes place in two groups in parallel. A maximum of 8 analog inputs is permitted per group.

Connectable sensorsThe associated characteristics are stored on the module for the connectable sensors and are activated through parameter assignment.

If a sensor characteristic is not already present, it is possible to enter any characteristic by defining interpolation points.

Parameter assignment screen form for FM 355 S

Comprehensive operating and monitoring functions facilitate testing and therefore reduce the duration of the startup phase.

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FM 355-2temperature controller module

The FM 355-2 temperature controller module is a function module based on the FM 355 and designed specifically for controlling temperature ranges.

Like the FM 355, the FM 355-2 has 4 channels and is available as the FM 355-2 C and FM 355-2 S.

Both versions of the module have an integrated online self-optimization facility and a backup facility.

ApplicationThe module is designed to control temperature ranges. Controllers with heating or active cooling functions can be implemented and optimized. In principle, other ranges with similar requirements can also be controlled.

Scope of deliverySee FM 355 (page 6).

A screen form is supplied with the module to facilitate control of the major controller functions. The user can integrate this easily into an OP27 project.

Functions

Control algorithmThe module operates with a PID algorithm.

Controller optimizationThe FM 355-2 has an integrated online self-optimization function, which can be used for controller optimization during operation without the need for a PG/PC.

Self-optimization can be started either when the ambient temperature is reached, via a control output jump (initial optimization) or when the controller reaches its operating point (follow-up optimization).

A quasi-stationary state is required to start optimization, i.e. actual value drift can be tolerated.

The control parameters are available as soon as the turning point of the step response is reached. Startup time is reduced considerably as a final state is not required.

The controller has a control zone to accelerate the approach to the operating point.

The controller’s response to setpoint changes can be changed and overshoots avoided by adjusting the attenuation of the proportional component in the event of setpoint changes.

The control output limits can be modified online.

Backup modeIn the event of a CPU stop or failure, the module can continue to control operation in backup mode (see FM 355). However, input through the operator panel is not possible in the event of a CPU failure.

ResolutionThe analog inputs have a resolution of 14 bits.

Sampling timeThe sampling time is 100 ms for each analog input used. If the compensation input is used, it must be taken into account along with the sampling time.

Increased accuracyThe accuracy of the FM 355-2 is greater than that of the FM 355. This is particularly beneficial when using thermocouples.

Connectable encodersAs the FM 355 but with the addition of the Type E thermocouple. However, the ��80 mV input is not available.

Temperature compensation when using thermocouples:

· Through external Pt100

· Internal temperature detector

· Parameterized value

Test functionsExtensive test functions and simulation options are available to offer assistance during the startup process.

Controller optimization on temperature controller module FM 355-2

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Modular PID Control

Modular PID Control is a collection of standard function blocks, which can be combined to create any type of control structure for SIMATIC S7/C7. The blocks can be connected using STEP 7, SCL, and CFC.

The following controller types are available:

· Continuous PID controller

· Pulse controller

· Step controller

ApplicationModular PID Control is suitable both for applications requiring extensive control structures and for applications in which memory must be saved and individual controllers from the standard module stock are sufficient for application requirements.

It is often worth purchasing the product even if the only blocks used are computational blocks such as dead band, polygon, scaling or time scheduler.

The main applications are in processing plants.

Scope of deliveryThe scope of delivery includes the following ready-to-use examples:

· Fixed setpoint controller with various outputs

· Single-loop ratio controller

· Multiple-loop ratio controller

· Blending controller

· Cascade controller

· Controller with precontrol

· Controller with feedforward control function

· Range selection controller

· Multiple variable controller

Sampling times down to 5 ms are possible in conjunction with the SM 334 analog module.

A software program, which consider-ably simplifies the commissioning of the PID controller, can be supplied for Mo-dular PID Control with SIMATIC S7/C7.

This software contains a control loop display with bargraphs and a curve recorder for displaying signal characteristics (see left figure on page 11).

Modular PID Control is available as a function block library for SIMATIC S7-300/S7-400 and C7.

FunctionsThe following technical functions have the same characteristics as in Standard PID Control:

· User-friendly parameter assignment

· Test functions

· Controller optimizing

· Transient response without overshoots

· Control algorithm for step controller

Combination with the PID Self-Tuner is also recommended here for online self-optimization of controlled systems for temperature.

Design of closed-loop control structures with CFCFor the first time, CFC V5.0 (Continuous Function Chart) and later supports the configuration and user-friendly interconnection of any type of control structure.

The 27 blocks of Modular PID Control are complement one another perfectly and can thus be combined both quickly and easily using the CFC graphic editor (see figure above).

Complex control structures can therefore be designed and tested reliably and clearly within a short time.

In particular when combined with CFC, Modular PID Control is a universal modular concept for solving a wide range of closed-loop control tasks.

Modular PID Control with the CFC graphic editor

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Standard PID Control is a preconfigured controller structure, which can be adapted to the control process simply by activating or deactivating functions.

ApplicationStandard PID Control is suitable for closed-loop control tasks of low or medium complexity: for temperature, pressure, flow and level controls.

Standard PID Control is particularly suitable for applications previously automated with compact controllers.

Scope of deliveryThe scope of delivery of the function blocks includes the following ready-to-use examples:

· Step controller with loop simulation

· Continuous controller with loop simulation

· Multiple loop ratio controller

· Blending controller

· Cascade controller

Siemens offers parameter assignment software for Standard PID Control that permits the functions of the standard function block to be easily utilized.

Functions

Test functionsA comprehensive range of test functions facilitates startup and diagnostics. As in the case of the controller modules FM 355/455 and Modular PID Control, a control loop display with bar graph and curve recorder are available for plotting the signal curves (see left figure on page 11). The windowing techniques of Windows allow the control structure, the parameters entered, and their effect on the result to be displayed simultaneously.

The curves plotted with the curve recorder can be saved to file for subsequent editing e.g. in MS Excel.

User-friendly parameter assignmentParameter assignment with the uniform, clearly arranged Windows user interface that supports intuitive working methods is particularly simple and is common to all function packages that rely on STEP 7. The clear controller structure allows functions to be selected or deselected simply using software switches (see figure above).

The user interface for parameter assignment means that changes to parameters can also be made with the CPU in the RUN status. In addition, changes to parameters are now also possible while the curve recorder or the loop display are active.

· Cursor positioned in input fields:Display of parameter name and address in instance block. The current value is additionally displayed in online mode.

· Cursor positioned on measuring points:Display of name and address in the instance block. The current value is additionally displayed in online mode.

The multi-instance data block (DB) benefits from user-friendly support from the control structure image, loop image, curve recorder and controller optimization.

Controller optimizationFor Standard PID Control, controller optimization is integrated in the parameter assignment software. Using this self-tuning function, controllers can be optimized very quickly even without precise knowledge of the controlled system. To initiate the function, the process is activated with a step change in manipulated variable or a modification in the setpoint. During the transient response, the process values are automatically recorded and displayed. The program calculates a mathematical module of the controlled system from the values, and determines the optimum control parameters for PI and PID controllers.

At each input step, the relevant information is displayed on the screen. This simplifies start-up and produces rapid results.

Transient response without overshootsIn the case of self-optimization, two different transient responses are available for selection: transient response of the control loop with overshoots of up to 10 %, or transient response without overshoots. This means that self-optimization can also be used when overshooting has to be avoided at all costs.

Standard PID Control

The clear controller structure of Standard PID Control

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Functions (continued)

Pulse controllerThe pulse controller is now combined with the continuous controller in one block including the conversion into a pulse/space signal (pulse generator). This simplifies the parameter assignment and startup of the pulse controller.

It is also possible to set the sampling time of the controller separately from the period duration of the pulse generator, so that the period duration can be longer than the sampling time.

The advantage of a shorter sampling time is the faster reaction of the controller to faults and operator input commands.

On the other hand, a longer period reduces wear on the final control element by reducing the pulse generator frequency. Oscillations in actual values are suppressed in that the effective period is automatically shortened.

A further advantage is the lower CPU loading since the pulse generator can be scanned at longer intervals.

The example of a pulse controller with 3-position output (HEATING - OFF - COOLING) facilitates startup of the temperature control.

Step controllerA control algorithm ensures that step controllers switch up to 50 % less often than conventional step controllers for the same control precision. This reduces wear on the final control elements and lengthens their service life consider-ably.

Extended manual/automatic switch-overThe following functions can be parameterized for the manual/automatic switchover:

· Bumpless manual/automatic switchover

· Manual/automatic switchover with bumps and corresponding jump in the manipulated variable for fast compensation of the deviation

· Tracking of manual value in automatic mode

Standard PID Control 2 Pulse module

2 Pulse moduleThe 2 Pulse module is a 2-channel, 15 mm wide ET 200S technology module for controlling actuators and valves.

In connection with the SIMATIC software control packages, e.g. Standard PID Control, it can output pulse-width-modulated control outputs, relieving the load on the CPU.

Areas of applicationThe 2 Pulse module can for example be used to control solid-state contactors or to switch cartridge type heaters.Operating modesThe 2 Pulse module operates in the following modes:

· Pulse output:A single pulse is output on the 24 V digital output.

· PWM (Pulse Width Modulation):

- A pulse-width-modulated signal sequence is output on the 24 V digital output (this operating mode is particularly suitable for control engineering); or

- A signal present on the 24 V digital input is output on the 24 V digital output with an ON/OFF delay

· Pulse train:A number of pulses set by the user is output on the 24 V digital output.

Optimization of Standard PID Control with PID Self-Tuner 2 Pulse module

PID Control PID temperature control

Areas of applicationPID Control provides a simple PID algorithm with which simple closed-loop control tasks can be directly solved. It is particularly suitable for simple control tasks.

PID Control for SIMATIC- S7-200 is a component STEP 7-

MicroWin programming software. - S7-300/S7-400 is integrated in

STEP 7, STEP 7-Mini CFC V1.1 and later as well as in the operating system of the CPU 313C/314C.

The number of controllers which can be implemented with the S7-300/S7-400 depends on the available memory space and the resulting total runtime. PID Control uses standard function blocks loaded into the CPU to solve the closed-loop control task.

Scope of delivery · SIMATIC S7-200

Controller block for implementing a continuous closed-loop controller, step controller or pulse controller

· SIMATIC S7-300One function block each for the continuous closed-loop controller, step controller or pulse generator module

Functions

Controller parameter assignment· PID Control for S7-200:

Simple programming thanks to a special “operations wizard”

· PID Control for S7-300/S7-400: User-friendly thanks to tabular overview (see figure).

PID Temperature Control

ApplicationIn addition to the universal PID Control function blocks, STEP 7 Version 5.1 SP3 and later offers two new controller blocks designed specifically for controlling simple temperature ranges.

· When developing the blocks, particular importance was placed on ease of handling

· For example, the function block interfaces were simplified considerably for the purpose of user-friendliness

The controller blocks can be used in heating or cooling applications. In principle, other ranges with similar requirements can also be controlled.

Scope of deliveryThe blocks are supplied integrated into STEP 7 together with parameter assignment software, a sample project and an electronic manual.

FunctionsIn addition to the PID Control functions described, the FB 58 TCONT_CP blocks also have functions for temperature control via an integrated online self-optimization facility. This means that a PG/PC is not required for optimization.

The blocks also have an integrated pulse generator module for implementing pulse controllers. In contrast to the solution with PID Control, the user does not have to interconnect any controller blocks. Programming is replaced by parameterization.

The FB 59 TCONT_S controller block is used to create step controllers.

The new parameterization software can be started directly from the SIMATIC Manager by double-clicking on the associated instance data block.

In addition to the familiar PID Control functions, the parameterization software also has a self-optimization wizard and a special installation screen form.

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Control parameters on the S7-300/400 using the example of PID Control

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The operating systems of the new 313C and 314C compact CPUs contain integrated closed-loop control blocks.

The following blocks are supplied as system function blocks (SFBs):

· Continuous controller

· Step controller

· Pulse generator module

The advantage: No user memory is used for the controller blocks.

Both the analog and digital I/O integrat-ed in the CPU can be used to implement the controller. Appropriate modules from the extensive SIMATIC range can also be used.

Special outputs for pulse width modulation are also available. These are suitable for the direct control of valves, actuators and switching devices.

FunctionsSame functional scope as PID Control.

Parameter assignmentThe “PID Control Parameterization” tool supplied with STEP 7 is used for parameter assignment.

ApplicationBy adding a function block, the PID Self-Tuner software package converts the PID controller into a self-optimizing PID or PI controller, enabling users to set PID controllers online and adapt them during operation.

The controller can be adapted to the process quickly and easily in online mode using easy-to-understand functions and systematically constructed examples.

PID Self-Tuner is ideal for optimizing temperature, level, and volumetric flow controllers.

The process must satisfy the following conditions:

· Stable asymptotic transient response

· Reasonable delay times (delay time < 0.3 * recovery time)

· Sufficient linearity in the selected working range

· Sufficient quality of measured signals

· Moderate process gains.

PID Self-Tuner is versatile: it can be combined with all controller products and used on both the SIMATIC S7-300/S7-400 and C7 hardware platforms.

Functions· Initial online tuning of PID controllers

· Online adaptation of the PID controller for follow-up optimization at the operating point

· Optimization of processes with heating and active cooling

· Manual mode

· Optimization for control zone response

· Test functions

Scope of delivery· Function blocks

- FB TUN_EC for optimizing continuous PID controllers

- FB TUN_ES for optimizing step controllers with and without position feedback

· Sample project

· Electronic manual

Integrated PID self-tunercontroller

PID-self-tuner

PID controller

PID parameters

ProcessSetpoint Actual value

Manipulatedvariable

PID self-tuner optimizes a PID controllerSIMATIC S7-300 CPU 314C

Technical specifications

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Control functions/modules PID Controlin S7-200

PID Control in STEP 7, CFC, CPU 313C/314C



Delivery form Software, Component ofSTEP 7-MicroWin

Software, Component of STEP 7, CFC, CPU 313C/314C

Software, Component of STEP 7 from V5.1 SP3

SW optional packages: function blocks (FB), parameterization software, manual

Application PID controller in S7-200 for simple closed-loop control tasks: up to 8 independent control loops

PID controller in STEP 7 for simple closed-loop control tasks

PID temperature controller in STEP 7 for simple heating or cooling controllers with integrated self-optimization

PID controller with off-the-shelf control structure and for control tasks of simple to medium complexity, incl. 5 examples

Properties

Number of channels 8 channels per CPU See I/Os See I/Os

Installation width Determined by CPU and I/Os Determined by CPU and I/Os

Backup capability -- -- -- --

Startup (test, diagnostics) -- -- With parameterization software

Online self-optimization of controller with controlled systems for temperature

-- In conjunction withPID Self-Tuner

Yes, for continuous and pulse controllers (integrated optimization)

In conjunction withPID Self-Tuner

Online self-optimization of controller with systems other than for temperature

-- In conjunction with PID Self-Tuner also for fill level and flow control

Controllers for ranges with similar characteristics can be optimized

With param. software

Elementary closed-loop control functions

PID algorithm Yes Yes Yes Yes

Output of continuous PID controller Yes Yes (FB 41, SFB 41) Yes (FB 58) Yes (FB 1)

Output of pulse controller Yes Yes (FB 41, SFB 41, FB 43 and SFB 43)

Yes (FB 58) Yes (FB 1)

Output of PID step controller -- Yes (FB 42, SFB 42) Yes (FB 59) Yes (FB 2)

Pulse generator Yes Yes (FB 43, SFB 43) Component of FB 58 Yes (component of FB 1)

Integrator Component of PID algorithm Component of PID algorithm

Differentiator Component of PID algorithm Component of PID algorithm

Physical scaling Yes (in the actual value and man. var. branches) Yes (in act. value branch) Yes (in setpoint, actual value and man. var. branches)

Dead band -- Yes (in the system dev.) Yes Yes (in the system dev.)

Conversion of analog input value Yes Yes (in act. value branch) Yes Yes (in act. value branch)

Conversion of analog output value Yes Yes (in man. var. branch) Yes Yes (in man. var. branch)

Limit monitor Yes (in the actual value and man. var. branches)

-- Yes (in act. value branch and in the system dev.)

Limiter -- Yes (in man. var. branch) Yes (in setpoint and actual value branches)

Yes (in setpoint and man. var. branches)

System deviation monitoring -- -- Yes Yes

Controller call distributor (for even distribution of CPU program runtime load)

-- -- -- Yes (FC 1)

Supplementary functions

Setpoint generator -- -- -- Yes (in setpoint branch)

Time scheduler -- -- -- Yes (in setpoint branch)

Ramp generator -- -- -- Yes (in setpoint and man. var. branches)

1st order delay element -- -- -- Yes (as filter in actual value branch)

2nd order delay element -- -- -- --

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Modular PID Control

PID Self-Tuner FM 355-2 CFM 355-2 S

FM 355 CFM 355 S

FM 455 CFM 455 S

SW optional packages:function blocks (FB), parameterization software, manual

Software, Optional package:function blocksincl. manual

FM 355-2 C, FM 355-2 S, incl. parameterization software, manual, and Getting Started

FM 355 C, FM 355 S, incl. parameterization software, manual, and Getting Started

FM 455 C, FM 455 S, incl. parameterization software, manual, and Getting Started

Modular FB building blocks for complex closed-loop control tasks with maximum flexibility and minimum memory requirements and shortest runtime, with 12 examples

FB for online self-optimization of PID temperature controllers, can be combined with Standard and Modular PID Control, FM 355/455 and any PID algorithm, with 3 examples

Module with off-the-shelf control structures and back-up capabilities when the CPU is at Stop or in the event of a CPU failure, integrated online self-optimization of controlled systems for temperature, tailored onboard I/Os.Specifically for FM 355-2C/S: specialist for temperature control, increased accuracy, improved control response.Specifically for FM 455C/S: self-optimization to speed up commissioning of control structures.

See I/Os See I/Os 4 4 8/16

Determined by CPU and I/Os Double width(80 mm)

Double width(80 mm)

Double width: 2 slots (50 mm)

-- -- Yes Yes Yes

With parameterization SW Irrelevant With param. software

In conjunction withPID Self-Tuner

In conjunction withPID controllers

Yes, PID controller with integrated online self-optimization. Initial optimization and adaptation, heating and cooling.

Yes, self-optimizing fuzzy controller

With parameterization software or with PID Self-Tuner

-- Ranges with similar characteristics can be optimized

Only with parameterization or in conjunction with PID Self-Tuner

Yes (FB 19) -- Yes Yes Yes

Yes (FB 13) -- Yes (FM 355-2 C) Yes (FM 355 C) Yes (FM 455 C)

Yes (FB 13 and FB 20) -- Yes (FM 355-2 S) Yes (FM 355 S) Yes (FM 455 S)

Yes (FB 14) -- Yes (FM 355-2 S) Yes (FM 355 S) Yes (FM 455 S)

Yes (FB 20) -- Yes (FM 355-2 S) Yes (FM 355 S) Yes (FM 455 S)

Yes (FB 8) -- Component of PID algorithm

Yes (FB 6) -- Component of PID algorithm

Yes (FB 16) -- Yes (in act. value branch)




Yes (FB 11) -- Yes (in act. value branch and in the system dev.)

Yes (FB 12) -- Yes (in setpoint and manipulated value branches)


Yes (FC 1) -- Not required

Yes (FB 25) -- -- -- --

Yes (FB 21) -- -- -- --

Yes (FB 22) -- Yes (in setpoint branch)

Yes (FB 9) -- Yes (as filter in actual value branch)

Yes (FB 10) -- -- -- --

‡

16





Supplementary functions (continued)

Adaptive dead band -- -- -- --

Dead time -- -- -- --

Non-linear static characteristic -- -- -- --

Linear scaling -- -- -- --

Linearization -- -- -- --

Override control -- -- -- --

Parameter control -- -- -- --

Range selection (split range) -- -- -- --

Analog-value switch -- -- -- --

Setpoint branch

Setpoint generator -- -- -- Yes

Time scheduler -- -- -- Yes-

Scaling -- -- -- Yes

Limiter -- -- -- Yes

Limitation of modification rate -- -- -- Yes

FC call (nested) -- -- -- Yes

Actual-value branch

Format conversion Yes Yes Yes Yes

Scaling Yes Yes Yes Yes-

Smoothing Yes -- -- Yes

Square-root function -- -- -- Yes

Monitoring of modification rate -- -- -- Yes

Limit monitor Yes -- -- Yes

FC call(nested) -- -- -- Yes

Closed-loop controller

Continuous PID controller Yes Yes Yes Yes

PID pulse controller Yes Yes Yes Yes

PID step controller Yes (programmable) Yes Yes Yes

Temperature controller Yes (programmable) Poss. (with PID Self-Tuner)

Yes Yes (with PID Self-Tuner)

Position feedback -- -- -- Yes

Connectable encoders

Thermocouples -- -- -- --

Resistance-type thermometer -- -- -- --

Voltage -- -- -- --

Current -- -- -- --

Inputs/outputs

Analog inputs per controller channel -- -- -- --

Digital inputs per controller channel -- -- -- --

Analog outputs per controller channel -- -- -- --

Digital outputs per controller channel -- -- -- --

Connection method -- -- -- --

‡


17

Modular PID Control

PID Self-Tuner FM 355-2 CFM 355-2 S

FM 355 CFM 355 S

FM 455 CFM 455 S

Yes (FB 1) -- -- -- --

Yes (FB 4) -- -- -- --


Yes (FB 23) -- -- -- --

-- Linearization of thermocouples B, E, J, K, R, S, and Pt100; root function; free polygon-based function

Linearization of thermocouples B, J, K, R, S, and Pt100; root function; free polygon-based interpolation

Yes (FB 17) -- -- -- --

Yes (FB 18) -- -- -- --


Yes (FB 26) -- -- -- --

Yes (FB 25) -- -- -- --

Yes (FB 21) -- -- -- --

Yes (FB 16 and FB 23) -- Yes Yes Yes


Yes (FB 22) -- -- -- --

Yes -- -- -- --

Yes (FB 2) -- -- -- --



-- -- Yes Yes Yes

Yes (FB 22) -- -- -- --


-- -- -- -- --

Yes (FB 19 and FB 13) -- Yes, temperature controller Yes Yes

Yes (FB 19, FB 13, FB 21) -- Yes, temperature controller Yes Yes

Yes (FB 19 and FB 14) -- Yes, temperature controller Yes Yes

Yes (with PID Self-Tuner) -- Yes Yes (fuzzy) Yes (fuzzy)


-- -- Type B, E, J, K, R, S Type B, J, K, R, S Type B, J, K, R, S

-- -- Pt100 Pt100 Pt100

-- -- 0 ... 10 mV ��80 mV, 0 ... 10 mV ��80 mV, 0 ... 10 mV

-- -- 0 ... 20 mA, 4 ... 20 mA 0 ... 20 mA, 4 ... 20 mA 0 ... 20 mA, 4 ... 20 mA

-- -- 1 1 1

-- -- 2 2 1

-- -- 1 (only FM 355-2 C) 1 (only FM 355 C) 1 (only FM 455 C)

-- -- 2 (only FM 355-2 S) 2 (only FM 355 S) 2 (only FM 455 S)

-- -- Standard front connector

‡





Manipulated variable branch

Manual/automatic switchover Yes Yes Yes Yes

Manual-value generator -- -- -- Yes

Scaling Yes Yes Yes Yes

Format conversion Yes Yes Yes Yes

Limiter -- Yes Yes Yes

Limiting of modification rate -- -- -- Yes

FC call (nested) -- -- -- Yes

Pulse generator -- Yes Yes Yes


Fixed setpoint control Yes Yes Yes Yes

Follow-up control -- -- -- Yes

Cascade control Yes (programmable) Limited Limited Yes

Ratio control -- Limited Limited Yes

Blending control -- -- -- Limited

3-component control -- -- -- --

Split range -- -- -- Limited

System environment

Central use S7-200 (CPU 214) S7-300, CPU 313C/314C, S7-400, C7-6xx S7-300, S7-400, C7-6xx

Distributed use -- Yes Yes Yes

PC-based Control Yes, as DP-, MPI slave -- -- --

System integration

Hot swapping of modules -- -- -- --

Supported by STEP 7-MicroWin STEP 7 from V3.0CPU 313C/314C from STEP 7 V5.1 SP3CFC V1.1

STEP 7 from V5.1 SP3 STEP 7 from V2.1

Function blocks -- Yes Yes Yes

Parameterization software Part of STEP 7-MicroWin Part of STEP 7 Yes

Integration with CFC -- Yes (PID Control is integrated into CFC)

Can be integrated --

Types of access Via user program Via function blocks Via FB/FC

Module replacement without prog. device

Yes, via memory module Yes, via memory card or micro memory card

Yes, via memory card

Authorization/licensing

Authorization -- -- -- Yes, for param. software

Runtime license for FB/FC/C library Irrelevant Required for each CPU

License for parameterization software Irrelevant Required for each PC/PG

Order No. group 6ES7810-2BC01-.... 6ES7810-4....-.... 6ES7810-4....-.... 6ES7830-2AA..-....

18

‡


Modular PID Control PID Self-Tuner FM 355-2 C FM 355-2 S

FM 355 CFM 355 S

FM 455 CFM 455 S






Yes (FB 21) -- -- -- --

-- -- -- -- --

Yes (FB 20) -- Yes (only FM 355-2 S) Yes (only FM 355 S) Yes (only FM 455 S)

Yes (examples 1 and 2) -- Yes Yes Yes

-- -- Yes Yes Yes

Yes (example 7) -- Yes Yes Yes

Yes (examples 4 and 5) -- Yes Yes Yes


-- -- Yes Yes Yes


S7-300 (from CPU 313), S7-400, C7-6xx S7-300, ET 200M on S7-Master, C7-6xx S7-400

Yes Yes -- -- --

-- -- In ET 200M on S7-Master --

-- -- Yes, with active backplane bus --

STEP 7 from V3.1 STEP 7 from V5.1 SP4 STEP 7 from V2.1 STEP 7 from V3.1

Yes Yes Yes, for data exchange with user program

Yes -- Yes Yes Yes

Yes, with CFC from V5.0 Yes Yes Yes Yes

via FB/FC (Function Call) Via function block

Yes, via memory card Yes Yes Yes

Yes, for param. software -- -- -- --

Required for each CPU Covered by FM 355-2 Covered by FM 355 Covered by FM 455

Required for each PC/PG Irrelevant Covered by FM 355-2 Covered by FM 355 Covered by FM 455

6ES78..-.....-.... 6ES7860-4AA..-.... 6ES7355-2....-.... 6ES7355-.....-.... 6ES7455-.....-....

‡

19

Need more information on SIMATIC based technology? But of course!

© Siemens AG 2002Subject to change without prior notice.

Siemens AktiengesellschaftAutomation and DrivesIndustrial Automation SystemsP.O. Box 4848, D-90327 Nuremberg

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Counting/Measuring with SIMATIC

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Cam Control with SIMATIC

Unlimited Motion Controlwith FM 458 in S7-400

Order No. 6ZB5310-0ET02-0BA7Produced in the Federal Republic of Germany26100/201356 SB 04021.

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Documents

Loop Control With SIMATIC