Hans berger automating with SIMATIC P1

Tự động hóa với Simatic

SIEMENS

Automating

with SIMATIC

Integrated Automation

with SIMATIC S7-300/400

Controllers, Software, Programming,

Data Communication, Operator Control and Process Monitoring

by Hans Berger

2nd revised edition, 2003

Publicis Corporate Publishing

Bibliographic information pubished by Die Deutsche Bibliothek

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ISBN 3-89578-223-8

Editor: Siemens Aktiengesellschaft, Berlin and Munich

Publisher: Publicis Corporate Publishing, Erlangen

© 2003 by Publicis KommunikationsAgentur GmbH, GWA, Erlangen

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Printed in Germany

Content

Content 1 Introduction

1.1 Components ofthe SIMATIC Automation System_

1.2 From the Automation Task to the Finished Program "

1.3 How Does a Prograrmamable Logic Controller Work?

1.4 How a Binary Signal Finds its Way from a Sensor into the Program

1.5 Structure ofa SIMATIC Projeet

2 SIMATIC Controllers — the Hardware Platform

2.1 Components of a SIMATIC Station 2.2 The Micro PLC SIMATIC S7-200

2.3 The Modular Mini Controller SIMATIC S7-300

2.4 SIMATIC §7-400 for Complex Control Tasks

2.5 High Availability with SIMATIC 2.6 _ Failsafety on SIMATIC S7 2.7 SIMATIC C7 Complete Systems 2.8 _ Process Connection with Digital Module: 2.9 Process Connection with Analog Modules 2.10 Function Modules Take the Load of the CPU

2.11 CP Modules Connect to Communication Networks

2.12 SIMATIC-S7 Intelligence: CPU Modules 2.13 CPUs with technology functions

2.14 SIMATIC PC-based Automation 2.15 Distributed Process Connections 2.16 SIMATIC DP Distributed VO

2.17 DP Slaves: Process Connection in the Vicinity of the Machine 2.18 The SIMATIC Programming Devices 3 STEP 7: Standard Tool for SIMATIC

3.1 Data Management in the SIMATIC Programmable Logic Controller

3.2 STEP7

3.3 SIMATIC Manager 3.4 Projects and Libraries

49

50

52

53 56

Programming the Logic Block Incrementally

Incrementally Programming a Data Block

Source-oriented Programming of Blocks

Help on Program Creation

System Diagnostics

Downloading the User Program to the CPU

Diagnostics during Program Testing

Monitoring, Modifying and Forcing Variables

Program Status

Testing User Programs Offline with S7-PLCSIM

PID Control with SIMATIC Software

Documentation in Wiring Manual Form with DOCPRO

Telephone Network Connections with TeleService

The Programming Languages 97

The Basic Programming Languages LAD, FBD and STL

Program Flow Control 103

Function Block Diagram FBD 108 Statement List STL + H2

Structured Control Language SCL I14

Continuous Function Chart CFC „ H16

Sequential Control S7-GRAPH 118 State Graph Control S7-HiGraph „120

Organization Blocks and Priority Classes - 123 Types of User Program Processing 124

Startup Program 126 Memory Reset, Retention 128 Main Program 129

Start Information 130

Process Images

Cycle Time, Reaction Time

Interrupt Processing (Overview)

Block Call and Block Parameters

Temporary Local Data

Static Local Data

Multi-Instances, Local Instances

148

149 150 152 154 1§§ - 156 158

SIMATIC Timers

SIMATIC Counting Functions Global Address Areas 162 Global Data Addresses 163 Absolute and Symbolic Addressing 164 Indirect Addressing 167 Data Types — Overview - 168 Elementary Data Types 169

Combined Data Types 172

Parameter Types 174 User-Defined Data Type (UDT) 175

Configuring Decentralized Peripherals

Addresses in the DP Master System

Operator Control and Process Monitoring 200

Push Button Panels PP7 and PPI7 - 201

Text Display TD17

Text Based Displays OP3, OP7 and OP17

Graphics Displays OP170B und OP270

Touch Panels TP170 und TP270

MP270B and MP370 Multi Panels

SIMATIC Panel PCs

Connection with SIMATIC S7 Stations

Configuring SIMATIC HMI Devices

Configuring HMI Devices Using SIMATIC ProTool

Process Diagnostics Using SIMATIC ProAgent

Visualization and Operator Control Using SIMATIC WinCC

Process Diagnostics in the User Program Using S7-PDIAG

1 Introduction

1 Introduction

1.1 Components of the SIMATIC Automation System

The SIMATIC automation system is a range of coordinated components with uniform me- thods of configuring, data management and data transmission

As programmable controllers (PLCs), the SIMATIC $7 controllers form the basis of the au- tomation system, SIMATIC S$7-200 is the micro system for the low-end performance range

—as a stand-alone solution or in a linear-bus network, The system solution that concentrates

on the manufacturing industry is the SIMATIC $7-300 with the compact CPUs and the in- novated standard CPUs And as the top-level device with the highest performance power of the SIMATIC controllers, the SIMATIC $7-400 enables system solutions for the manufac- turing and process industries

The SIMATIC C7 controllers are designed as control systems for machine control and offer

PLC performance power including visualization in the smallest possible space Human ma-

chine interface functionality is carried out using a line-oriented or graphics-based operator panel in which the integral controller provides the PLC performance power on the basis of

a SIMATIC $7-300

SIMATIC PC-based Automation supplements the SIMATIC controllers with PC-based con- trollers SIMATIC WinAC is the integration platform for control, data processing, commu- nication, visualization, and technological functions PC-based Control is available as a pure-

ly software solution (software PLC) and as a PC plug-in card (slot PLC) Embedded Control with a software PLC under Windows CE supplements the SIMATIC product range with a new class of devices for machine-level control and visualization

The SIMATIC DP distributed I/O system allows you to install the I/O modules connecting the PLC to the machine or plant in the vicinity of the machine, at a distance from the PLC The distributed [/Os are linked to the central controller ~ with minimum wiring - by means

of the PROFIBUS network The user program treats distributed I/O modules in the same way

as central /Os

SIMATIC HMI stands for Human-Machine Interface From the humble text display to the graphics-capable operator station, these products provide all the facilities you need for op- erating and monitoring a machine or plant, Powerful software indicates the state of the plant

with event and fault messages, manages recipes and measured value archives, and provides

support with troubleshooting, servicing and maintenance

SIMATIC NET links all the SIMATIC stations together and ensures trouble-free commu- nication One cable is all you need to network all the SIMATIC stations through their integral

MPI interface They can then exchange data or you can communicate with all the stations in

the network from a central programming device A range of bus systems with different per- formance specifications make it possible to include non-SIMATIC devices in networks, from field devices in the plant to computers at plant management level

12

SIMATIC controllers control ö6ãWgSe

the machine or plant | | | of the pint i operation

SIMATIC NET Networking for the ex-

change of data and pro-

gramming at a central point

STEP7

and optional packages

Hi) = | eee

Distributed I/Os extend the interface configuring and

between PLC and machine/plant a runtime software

Figure 1.1 Components of the SIMATIC automation system

The STEP 7 Standard Tool is the keystone of the Totally Integrated Automation concept,

with its uniform configuration and programming, data management and data transmission You use STEP 7 to configure the SIMATIC components, assign parameters to them and pro- gram them SIMATIC Manager in STEP 7 Basic is the central tool for managing the auto-

mation data and the necessary software tools It keeps all the data for an automation project

in a project folder with a hierarchic structure and stores standard software and re-usable user

software in libraries

The main activities performed with STEP 7 are:

> Configuring the hardware, that is arranging modules in racks, assigning addresses to them

and setting the module properties

> Configuring communication connections, that is defining the communication partners and connection properties

> Writing the user program for the PLC in the programming languages Ladder Logic (LAD), Function Block Diagram (FBD) or Statement List (STL) and testing the program

online on the controller

Various optional packages are available to extend the functions of the STEP 7 Standard Tool For example, the Engineering Tools provide additional programming languages and pro- gramming methods, and there is also special configuring software for the human-machine interface, configuring software for communications processors and runtime software, such

as closed-loop control functions for the user program

13

1 Introduction

1.2 From the Automation Task to the Finished Program

When you start to solve an automation problem, you have to ask yourself what type of PLC

you are going to use If the machine to be controlled is a small one, will an S7-200 be big enough or do you need an $7-300? Is it better to control the plant with an S7-400 or with a

pair of S7-300s? Compact central /Os in the control cabinet or distributed 1/Os in the plant?

The following is a general outline of the steps that lead from the automation task to the fi-

nished program In individual cases with concrete requirements, some steps can be omitted

or others may need to be added

Choosing the hardware

There are many criteria for selecting the type of controller For “small” control applications

the main criteria are the number of inputs and outputs and the size of the user program For

larger plants you need to ask yourself whether the response time is short enough, and whe-

ther the user memory is big enough for the volume of data to be managed (recipes, archives)

To be able to estimate the resources you need from the requirements alone, you need a lot of

experience of previous automation solutions; there is no rule of thumb

A production machine will probably be controlled by a single PLC, In this case, the number

of inputs/outputs, the size of the user memory and, possibly, the speed (response time) will

enable you to decide between the S7-200, $7-300 or the $7-400 How is the machine to be operated? (This will determine whether you should use separate operator control and moni- toring devices from the SIMATIC HMI range, or SIMATIC C7 complete systems)

For plants spread over several locations, it is often more cost-effective to use distributed I/Os

rather than central I/Os In many cases, this not only reduces the wiring overhead, but dele~ gating control tasks to their actual location can also cut the response time and the engineer- ing costs (decision in favor of SIMATIC DP distributed I/O, possibly even “intelligent” DP

slaves with their own user program for preprocessing the signals)

Distributed automation solutions have their advantages: the user programs for the different parts of the plant are shorter, have faster response times, and can often be started up inde-

pendently of the rest of the plant The necessary interchange of data with a central controller

within the SIMATIC system is extremely easy using SIMATIC NET and the coordinated

communication functions

Which programming language?

The choice of programming language depends on the task If it mainly consists of binary signal processing, the graphical programming languages LAD (Ladder Logic) and FBD (Function Block Diagram) are ideal For more difficult tasks requiring complex variable handling and indirect addressing, you can use the STL (Statement List) programming lan-

guage, which has an assembly language format SCL (Structured Control Language) is the

best choice for people who are familiar with a high-level programming language and who mainly want to write programs for processing large quantities of data

14

1 Introduction

There are different programming methods that make programs easier to write: S7-GRAPH for sequential control, state graph programming with $7-HiGraph, and S7-CFC (Continuous

Function Chart) for linking together existing functions Ready-made blocks are also avai-

lable to help you write user programs, for example for programming control loops or con- figuring messages

Creating a project

All the data for your automation solution is collected together in a “project.” You create a project using the STEP 7 basic software A project is a (software) folder in which all the data

is stored in a hierarchic structure The next level down from the “project” are the “stations,”

which contain one or more CPUs with a user program All these objects are folders, which

can contain other folders or objects that represent the automation data on the screen You use menu commands to insert new objects, open these objects and automatically start the neces-

sary tool to work with them

Example: A station contains an object called Hardware You double-click this object to start the Hardware Configuration tool, which is the tool you use for configuring the hardware of the station, that is you arrange the modules in a rack, and assign addresses and parameters

to them In SIMATIC you do all this with software: you define the properties of the modules

in dialog boxes with support from the online Help

Writing, debugging and saving the user program

The user program contains all the instructions and arrangements programmed by the user for

processing signals to control the machine or plant to perform the required task Large, com-

plex tasks are easier to solve if they are divided into small, manageable units, which can be

programmed in “blocks” (subroutines) The division into blocks can be process-oriented or function-oriented In the first case, each program unit corresponds to a part of the machine

or plant (mixer, conveyor belt, drilling assembly) In the second case, the program is divided

up according to control functions, for example signaling, communication, operating modes

In practice, a mixture of the two types of structure is generally used

The objects used for creating programs are the symbol table and the compiled blocks, and —

depending on the programming language — the program source files You double-click a pro- gram source file or block object to start the program editor and then you can enter or modify the program for the block You write the user program “offline” and save it on the hard disk

of the programming device

To start up the system, you connect the programming device to the CPU, download the program to the user memory of the CPU and test it You can monitor and modify the values

of the variables and observe the program flow Extensive diagnostics functions enable you

to identify the location and cause of errors very quickly You can test individual sections of

your program offline in advance with the PLCSIM optional software When you have

successfully started up the system, you copy the user program to a non-volatile flash EPROM memory card and generate the project documentation, for example in the form of

a circuit manual with DOCPRO With STEP 7 you can save an entire project as a com-

pressed file

15

1 Introduction

1.3 How Does a Programmable Logic Controller Work?

In conventional control engineering, a control problem is solved by wiring up contactors and relays individually to perform the required task Contactor and relay controllers and elec- tronic controllers assembled from separate components are referred to as hard-wired pro- grammed controllers The “program” is in the wiring Programmable logic controllers, on

the other hand, are made up of standard components The desired control function is imple-

mented by a user program in the CPU

SIMATIC S7 automation systems are based on a central programmable logic controller The solution to the automation task is stored in the user memory of the CPU in the form of pro- gram instructions The CPU reads the instructions one after the other, interprets their con- tents and ensures that they are executed

The CPU processes instructions in MC7 machine code, either direct or by interpretation

Whichever programming language you use to write the user program, it is always converted into MC7 instructions STL (Statement List) is the programming language that is the most similar to MC7 machine code

Logic operations using binary signals | | Example: "1 5.2” stands for

\ \ input byte 5, bit 2

<>

Here is an example: When the two inputs I 5.2

and [ 4.7 both have the signal state “1”, output

Q8.5 is also to be set to signal state “1”, other-

wise it is to be set to “0” The program in MC7

" ° © > Previous logic operation

Check input I 5.2 ("first

check") This signal

state becomes the result

of logic operation (RLO)

Check input I 4.7, perform

stored RLO and store the

result as the new RLO

Assign the stored RLO to

Next logic operation

oat oP Sel/Reset function

The CPU now processes this program one in-

struction at a time When the instruction A I

5.2 is processed, the relevant input module se-

lects the sensor at the specified address, input

15.2 The CPU checks the signal state (“sta-

tus”) of the selected sensor If this is the first

check instruction after a control instruction,

output byte 8, bit 5

the CPU immediately stores the status of the

address checked in the RLO (result of logic op-

16

How a programmable logic controller

processes a bit logic instruction

1 Introduction

eration) memory without performing a logic operation on it When it processes the next check instruction, the CPU then performs the required logic operation on the result of the

check and the result of the previous logic operation stored in the RLO memory The result

of this logic operation is stored as the new result of logic operation The CPU then processes

the next instruction in the program In the example, it processes the Output instruction by

saving the result of logic operation at the specified address

When the “old” result of logic operation has been saved, the next check instruction starts a

new logic operation in which the result of the first check becomes the new result of logic

operation

Cyclic program processing

The CPU of a programmable logic controller processes the user program continuously The program continues to run even if no action is required from outside, for example if the ma- chine is at a standstill This makes programming easier For example, you can write your

Ladder Logic program just as you would draw a relay ladder logic diagram or you can write

your Function Block Diagram program as though you were connecting electronic compo- nents Broadly speaking, a PLC is like a contactor or relay controller: the many logic ope-

rations in the program are all effective “in parallel” at the same time

How can this be so if the controller operates sequentially?

When the power is switched on, the CPU pro- Power ON

cesses the operating system, and a startup pro- |

gram if there is one Then it goes on to the main

program It processes the logic operations for Start STARTUP

the first time The CPU checks the input sig- mm mode

nals, performs logic operations on them and

sets or resets the outputs

When the CPU has executed the main Program Updating inputs

right to the end, it starts to process it again and outputs RUN

mode

from the beginning It checks the inputs again, — 1 -

performs the logic operations on them and sets

or resets the outputs again In this way the Executing

states of the outputs are adjusted to suit the main program

changing states of the inputs at very short in- Gi

tervals (the response time depends on the

length of the main program to be processed)

This type of cyclic program processing is typ-

ical of programmable logic controllers For

special applications, cyclic program process-

ing can also be interrupted by hardware inter-

rupts or time-of-day interrupts (at fixed inter- Cyelic program processing in a pro-

vals, for example) grammable logic controller

7

1 Introduction

1.4 How a Binary Signal Finds its Way from a Sensor

into the Program

In order to do its job, the CPU in the programmable logic controller needs to be linked to the machine or plant it is controlling This link is provided by input/output modules, which are connected to the sensors and actuators in the machine or plant

Connection to the programmable logic controller, module address

When you wire up the machine or plant, you decide where each signal is to be connected to

the PLC An input signal, for example the signal from momentary-contact switch +HP01-

$10, which means “Switch on motor,” is connected to a particular terminal on an input mo-

dule

This terminal has an “address” (for example, byte 5, bit 2) The address of a module is either

fixed by the slot in which the module is installed in the rack or you can set it with the STEP 7 Hardware Configuration tool The module addresses are arranged in bytes (groups of 8 bits/ binary signals) The module starting address is the lowest address of the module If this is 4, for example, and the module has more than one byte, the address of the next byte of the mod- ule is automatically 5, and so on The bit addresses in each byte are numbered from 0 to 7

Absolute and symbolic addresses

The CPU executes the user program (main program) cyclically: when it comes to the end of the program, it starts processing it again from the beginning Every time it processes the pro- gram, the CPU first automatically copies the signals from the input modules to the process image input table, an area in the system memory of the CPU The signal can then be located under its address in the process image, for example input I 5.2 The expression “I 5.2” is the absolute address If there is power at the relevant input terminal, input I 5.2 has signal state

“In,

You can give this input a name, either right away when you are configuring the hardware or later on You do this in the symbol table by entering alphanumeric symbols that convey the meaning of the input signal at the absolute address, for example “Switch on motor.” The

expression “Switch on motor” is the symbolic address You can assign names to all the sig-

nals in the symbol table and use these names to address the signals more clearly in the user

program

Outputs control the machine or plant

The outputs are treated in a similar way They have addresses in a memory area of the CPU

called the “process image output table” In the program, an output is set or reset — in the

process image — depending on certain conditions At the end of the program, the CPU copies the process image output table to the output modules and the relevant terminal controls the actuator connected to it, for example a contactor, a lamp or an electronic device

18

single signal, that is a single bit

For the user program it makes no difference whether you connect the sensors and actuators

to modules installed in the central rack, or to distributed /O modules installed in the plant and connected to the central controller by a bus system You address the input and output

modules in the same way in both cases, that is you check the sensors in the process image input table and control the actuators by setting or resetting the outputs in the process image

output table

Sensor Programmable controller

Input vo Process image module area input table

0 |Byten 0 | Byte 4

ae — 01234567

Byte 4 TTT) eves + 7 ấ =

0 |Bylen+l 0 |Byte8 +

7 =—r Slot Module Absolute

address starting address address

Configuration table Symbol table í

Slot [Type ] Address |[Symmbgi [Addrass [Data type

5 DI16 4 Switch on møter - 15:2 BOOL

User program “Switch, on motor” 15.2

Ladder Logic (LAD) j

User program “Switch “ l8:

Function Block Diagram (FBD) "An na TP * fal

User

Statement List (STL) A “Switch on motor” A152

Figure 1.4 Module address, absolute address and symbolic address

(How a signal from a sensor is checked in the program)

19

1 Introduction

1.5 Structure of a SIMATIC Project

When you configure an automation system with STEP 7, you represent the “real” objects

with “logical” objects in a SIMATIC project The object hierarchy is modeled on the real

hardware configuration, that is a project contains one or more PLCs (Stations), each station contains a CPU, and this contains a user program made up of a symbol table, source files and compiled code (Blocks) The screenshot shows the SIMATIC Manager project window In the left pane you can see the structure of the project with its folders These contain the folders and objects that appear in the right pane A station, for example, is a folder, which can con-

tain other folders or objects If you double-click an object in the right pane, the tool for ed-

iting the object opens For example, a double-click on a subnet starts the network configura-

tion software, and a double-click on a block (in the Blocks folder) starts the Program Editor

SE nse © @ $7 Progam // The “real” objects in an automa-

Figure 1.5 An automation system represented by “logical” objects in a SIMATIC project

2 SIMATIC Controllers — the Hardware Platform

2 SIMATIC Controllers — the Hardware Platform

SIMATIC programmable logic controllers — the core of the automation systems ~ control production machines, manufacturing plants or industrial processes We distinguish different

controller “families” with regard to their range of performance and field of application:

> SIMATIC S7 controllers are at the heart of the SIMATIC hardware They are available

in three versions:

- SIMATIC $7-200, the compact micro PLC

~ SIMATIC $7-300, the modular PLC of the mid performance range

- SIMATIC $7-400, the modular PLC of the upper performance range

The $7-200 station consists of a basic unit and can be expanded with additional modules

In S7-300/400 stations, the power supply unit, the CPU module and the /O modules are

installed in the same mounting rack This centralized configuration can be extended with

expansion racks for the installation of additional /O modules The expansion rack may

be a remote installation, that is it can be placed at a distance from the central rack You

use the STEP 7 Micro programming language to program the SIMATIC $7-200 control-

ler STEP 7 with its different programming languages is provided for the controllers of

the SIMATIC $7-300/400 series

> SIMATIC C7 is a series of complete units combining an $7-300 controller and an oper-

ator panel

SIMATIC C7 stations have integrated inputs/outputs They can be expanded in a central- ized arrangement by adding input/output modules of the S7-300 range You use the stan-

dard STEP 7 programming tool to program SIMATIC C7 controllers

> SIMATIC WinAC is the generic term for the program packages of SIMATIC PC-based

Automation WinAC runs on a standard PC under a Windows operating system PROFI-

BUS-DP forms the link to the process

With SIMATIC PC-based Control, the controller can take the form of a purely software solution (Software PLC) or a plug-in card (SlotPLC)

In SIMATIC Embedded Control, WinAC MP runs under Windows CE on an MP 370

Multi Panel

> SIMATIC DP are modules that are installed in the vicinity of the machine and connected

to the master station of a PROFIBUS DP network Many of the available SIMATIC CPUs

provide an integrated DP interface which greatly facilitates the connection of distributed V/O You can also use this standard bus interface to connect third-party devices to a SI-

MATIC controller

SIMATIC stations communicate with each other over subnets The operator control and pro-

cess monitoring devices of the SIMATIC HMI series are also connected to these subnets SIMATIC NET recognizes MPI, PROFIBUS and Industrial Ethernet as subnets You can also connect a single device, such as a printer, through a serial point-to-point connection

21

2 SIMATIC Controllers — the Hardware Platform

A complete programmable controller including all I/O modules is called a “station.” An S7-

300/400 station consists of at least one module rack accommodating the power supply and the CPU module 1/O modules establish the link to the machine or plant The components of

a SIMATIC station are described below:

> Mounting rack

Accommodates and connects the individual modules The $7-300 uses a simple DIN rail;

its length is determined by the number of modules The $7-400 has an aluminum rack of

fixed length with a backplane bus and bus connectors

> Power supply (PS)

Provides the internal supply voltage; the input voltage is either 120V/230V AC or 24V

De

t> Central Processing Unit (CPU)

Stores and processes the user program; assigns parameters to the modules; handles the communication with the programming device, the modules and additional stations over the MPI bus; can be equipped with an integrated DP interface for DP master or slave op-

eration

b> Interface module (IM);

Connects the mounting racks with each other

Handles complex or time-critical processes independently of the CPU module, e.g.,

counting, position control and closed-loop control

> Communications processor (CP)

Connects the SIMATIC station with the subnets, such as Industrial Ethernet, PROFIBUS FMS, actuator/sensor interface or serial point-to-point connection

The rack-mounted backplane bus comprises two buses: the I/O bus for the fast exchange of

input/output signals, and the communication bus for the exchange of larger amounts of data The connection between the communication bus and the CPU’s MPI interface enables FM

and CP modules with communication bus interface to communicate with the MPI bus sys- tem It is thus possible to program these modules through the programming device interface

of the CPU

The distributed I/O modules connected to a SIMATIC station are also part of this station, A

SIMATIC station can have several DP masters which communicate with the DP slaves, that

is the field units, over one or several PROFIBUS DP subnets The DP slaves are integrated

in the address area of the centralized I/O system and are principally treated just like the /O modules installed locally, in the central and expansion racks

22

2 SIMATIC Controllers ~ the Hardware Platform ‘

2 SIMATIC Controllers — the Hardware Platform

2.2 The Micro PLC SIMATIC 87-200

The SIMATIC S7-200 is a compact micro PLC replacing relay and contactor control arrangements Also, SIMATIC $7-200 controllers increasingly replace specific electronic circuits in mechanical and system engincering applications SIMATIC S$7-200 can be used

as a stand-alone system or in a network with other control systems Various expansion mo- dules for the connection to the machine or plant are available The programming language used is STEP 7 Micro

Compact-type basic modules and expansion modules

Various basic modules with different functionality are available The basic module contains

the CPU, integrated inputs and outputs using 24V DC or 100V/120V to 230V AC and relay

outputs Number and type of the integrated inputs and outputs depend on the type of CPU used Fast alarm and counter inputs enhance the module’s real-time performance, Its inte- grated potentiometer allows you to set a digital value simply with a screw-driver — no pro- gramming device is needed

You can increase the number of inputs/outputs by connecting an expansion module Such modules are available for both digital and analog inputs/outputs The expansion modules are

snapped onto the rail (e.g., standard DIN rail) next to the basic module and electrically con-

nected by means of a bus connector

Human machine interfacing on the S7-200

The TD 200 Text Display and the TP 070 Touch Panel are available especially for the S7-

200 The TD 200 is linked to the CPU via the PPI connection, and the TP 070 is connected

using MPI or PROFIBUS DP The possible uses of these devices include displaying message texts, setting outputs, and controlling small machines or plants

Communication capability just like a “large” station

All S7-200 central processing units are equipped with a PPI interface (Point-to-Point Inter- face) This is the interface through which the CPUs are programmed The PPI interface also allows you to interconnect several $7-200 central processing units (up to 31 CPUs) and con- nect a programming device, operator panel or TD200 text display unit Data exchange is based on the master-slave principle The rate of transmission is 9.6/19.2/187.5 Kbit/s The PPI interface can also use a bit-oriented communication protocol at up to 38.4 Kbits/s which you can create yourself making use of the user program’s programmable communi-

cation function In this way it is possible to connect any terminal that has an RS 232 inter-

face, for example, a bar-code reader using the ASCII protocol

Due to the integrated interface, some of the $7-200 central processing units can also be con-

nected to an MPI subnet to serve as a slave device and thus exchange data with SIMATIC

stations of other SIMATIC series

The AS Interface Master CP 242-2 allows you to connect up to 31 AS interface slaves to one S7-200 station and thus increase the number of available inputs/outputs In addition to its AS

interface master function, the CP 248-2 provides a PROFIBUS DP interface which allows

you to use S7-200 stations as DP slaves

24

2 SIMATIC Controllers — the Hardware Platform

combining I/O bus and communication bus functionality connects the modules with each

other Bus connectors link one module to the next This means that the length of the bus al-

ways depends on the number of modules plugged in and never extends beyond the last mo-

dule

The module slots in the mounting rack are numbered in consecutive order: slot 1 for the power supply unit, even if not installed; slot 2 for the CPU; slot 3 for the interface module

IM, even if not installed Slots 4 to 11 are reserved for the /O modules which must be

plugged in one next to the other without any gaps Their is no connection between the mo-

dule slot number and the module width

Expansion racks

If a single-row configuration is not sufficient for your requirements, you can use (from CPU

314 onwards) a two-row configuration (with IM 365) or a maximum configuration of four rows (with IM 360 and IM 361) with up to 32 YO modules

The IM interface module is installed between the CPU and the first /O module Like the cen- tral rack, the expansion rack, too, is a DIN rail with snap-on modules The receiver IM, which

establishes the connection with the central rack, is installed in module slot 2 A transmitter IM

for the connection to another module rack is installed in slot 3 Slots 4 to 11 are reserved for

the I/O modules which must be plugged in one next to the other without any gaps

Versatile use

A wide range of standard $7-300 CPUs covers the low-end to mid performance ranges in the manufacturing industry With a comprehensive range of modules and flexible networking facilities, the requirements for optimal adaptation to the controlled machine or plant ate met

In addition to the standard CPUs, the S7-3xxC compact CPUs also contain technological functions (counting, measuring, closed-loop control, positioning) with integral inputs/out- puts, thus making compact design of mini controllers possible

The failsafe SIMATIC $7-300F programmable controller is used in manufacturing industry

to meet increased safety demands It complies with safety requirements to SIL 3 in accor- dance with IEC 61508, AK6 in accordance with DIN V 19250 and Cat 4 in accordance with

EN 954-1

The SIMATIC S7-300 outdoor has been developed for the use in hostile ambient condi- tions These modules support an extended temperature range from —25°C to +60°C, and have

higher vibration and shock resistance in accordance with IEC 68 Part 2-6 They are resistant

to humidity, moisture condensation and icing in accordance with IEC 721-3-3, Class 3 KS All other technical characteristics are identical to those of the standard modules

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2 SIMATIC Controllers — the Hardware Platform

2.4 SIMATIC S7-400 for Complex Control Tasks

Central rack

The S7-400 mounting rack, an aluminum DIN rail of a fixed length with backplane bus and

bus connectors, can be used as a central rack (CR), an expansion rack (ER), or as a combi-

nation of both (UR, universal rack)

The S7-400 central rack is available with 18, 9 or 4 module slots (UR1, UR2 or CR3) of fixed mounting widths The power supply unit and the CPU module also occupy module slots, possibly even 2 slots per module Normally, you start the module arrangement by in-

stalling the power supply module at the far left of the mounting rack, followed by the CPU

and the I/O modules You may choose the slots as required It is not necessary that the mod-

ules are plugged in next to each other; gaps are allowed Insert the interface modules for the

connection to expansion racks in the right-hand part of the mounting rack The backplane

bus, comprising the parallel I/O bus and the serial communication bus, interconnects the

module slots

The CR2 segmental rack allows you to use two CPUs on a common power supply The CPUs

exchange data over the communication bus, but each uses its own I/O bus to communicate

with its I/O modules The left segment provides 10 module slots, the right segment 8 module

slots

The UR2-H segmental rack consists of 2 segments with 9 module slots each You can use it

as a central rack or as an expansion rack in standard $7-400 stations or high-availability S7-

400H stations Each segment requires its own power supply; I/O bus and communication bus

are separate,

Universal rack URI

All module slots are connected with the communication

bus and the /O bus The rack can have a standard or a

redundant power supply unit

Central rack CR2

“The rack's 18 module slots are divided into two seg-

ments of 10 and 8 slots The I/O bus is restricted to the

related segment The segments have a common power

‘supply unit

Universal rack UR2-H

The rack is divided into two segments of 9 module

slots The backplane bus is split A second power sup-

ply is therefore required

Figure 2.2 Backplane bus in the SIMATIC S7-400 central racks

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2 SIMATIC Controllers — the Hardware Platform

Expansion racks

If there is insufficient space for the I/O modules in the central mounting rack, or if you want

to install modules at a distance, you supplement the station with one or more expansion units Universal racks and expansion racks can be used as expansion units, with up to 2] on one central rack The send and receive interfaces that are used in pairs transmit the signals over various distances

Interface pair IM 460-0 | IM 460-1 | IM 460-3 | IM 460-4

IM 461-0 | IM 461-1 | IM461-3 | IM461-4 Max distance Sm lãm 102m 605 m Max number of connectable expansion racks 8 2 8 8

‘Transferred buses vorc vo vo+c vo

Supply voltage is transferred no yes no no

The ER1 and ER2 expansion racks with 18 or 9 slots are intended for “simple” signal mo- dules which do not trigger process alarms, do not require a 24 V DC supply over the P bus nor a backup supply, and are not equipped with a communication bus interface The URI and UR2 racks are equipped with a communication bus if they are used either as central racks or expansion racks with the id numbers | to 6

Connection of SIMATIC S5 modules

The IM 463-2 interface module is used for connecting SIMATIC $5 expansion units (EG

183U, EG 185U, EG 186U, ER 701-2 and ER 701-3) to an $7-400 station These expansion

units can again be expanded in a centralized arrangement, An IM 314 interface module in the S5 expansion unit establishes the connection In such an arrangement you can use any of

the digital and analog modules listed for the specified expansion units In a decentralized set-

up, you can connect up to 16 S5 expansion units to one $7- 400 station

If you want to use a single SS module in an S7-400 station, you have to make use of an ada- pter module

Enhanced performance with multiprocessing

You can convert the S7-400 station into a multiprocessing controller by inserting several

CPUs (4 max.) Make sure to select CPUs that are specified for this type of operation which

is also called “multicomputing.” As soon as you install more than one CPU, the programma- ble controller will automatically assume multiprocessing operation All CPUs have the same operating mode This means they start together and also all of them go to STOP if one of the CPUs fails Each CPU executes its own user program independently of the other CPUs

Each 1/O module is assigned to one specific processor This includes its address and alarms

All /O modules are located in the same I/O bus segment, This means that you must give

them different addresses although they refer to different CPUs The same rule applies to

distributed /O modules Although each CPU can operate one or several DP master systems independently from the other processors, each centralized and distributed module must have

its unique address (I/O bus addresses) in the overall system

27

2 SIMATIC Controllers ~ the Hardware Platform

For slow processes: software redundancy with standard components

The standard SIMATIC $7-300/400 components allow you to build a redundant system based on software redundancy In such a redundant setup, a standby station assumes control

of the process if the master station breaks down High-availability through software redun-

dancy is suitable for slow processes as it could take up to several seconds — depending on the controller performance — before the standby station is ready to take over During this period, all process signals are “frozen.” The standby station then continues processing, starting with

the most recent valid data from the master station

Both CPUs exchange the current data over a subnet which can be any random subnet For

this, they can make use of existing communication links The single-channel redundancy of the input/output modules is implemented with distributed /O modules (ET 200M with IM 153-3 interface module for redundant PROFIBUS DP) The individual CPUs can also con- trol non-redundant I/O, both in centralized and distributed arrangements

Use the optional software package “Software Redundancy” to configure the redundant sy-

stem

High availability using hot standby: SIMATIC S7-400H

SIMATIC $7-400H is a highly available programmable logic controller using a redundant

configuration with two 417-4H central processing units, each equipped with a synchroniza-

tion module for data synchronization through a fiber-optic cable Both devices operate in hot

standby mode with automatic, bumpless switchover to the standby unit which takes over full

control of the user program if the primary unit breaks down

The high-availability system comprises either two separate central racks (UR1/UR2) or one split central rack (UR2-H) Next to the power supply and CPU modules which are always backed up by a standby unit, you can insert /O modules with standard or increased avai-

lability

@ Single-channel configuration

The VO modules are not duplicated and are connected to one of the subsystems, in a cen- tralized or distributed arrangement The redundancy connection ensures that the signal are available to both subsystems The user program is the same for both subsystems If one subsystem fails, the /O modules connected to the faulty subsystem can no longer

communicate

@ Switched single-channel configuration

The /O modules are not duplicated and connected in a distributed setup using the ET

200M station with active backplane bus The I/O arrangement must be symmetrical This

means that each subsystem has access to the I/O modules through the IM 153-3 interface module equipped with a redundant DP interface The high-availability system uses only one interface at the time The redundancy connection ensures that the signal states are available to both subsystems, The user program is the same for both subsystems

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2 SIMATIC Controllers ~ the Hardware Platform

© Unilateral redundant configuration

The I/O modules are inserted in pairs in the two subsystems, in one central rack The re- dundancy function is implemented in the user program

@ Switched redundant configuration

The I/O modules are inserted in pairs in two ET 200M stations with active backplane bus The redundant IM 153-3 interface module connects the ET 200M stations to both sub- systems The redundancy function is implemented in the user program

‘You can also implement a redundant exchange of data by backing up the Industrial Ethernet

or PROFIBUS subnet In addition to the active connection, you can install up to 3 redundant connections which the operating system can use if the primary connection fails Program- ming highly available connections does not differ from programming standard connections

Use the optional software package “S7 H Systems” to configure the redundant system

@ Unilateral single-channel configuration @ Switched single-channel configuration