Siemens Simatic S7-300 User manual

Preface, Contents
Requirements for Working with
the Primer 1
Defining and Structuring the
Control Task 2
Installing and Wiring Your
S7-300 3
Working with the STEP 7
Programming Software 4
Configuring and Assigning
Parameters to Your S7-300 5
Programming Logic Blocks with
STEP 7 6
Downloading and Testing Your
User Program 7
Glossary, Index
C79000-G7076-C500-01
S7-300 Programmable
Controller
Quick Start
Primer
SIMATIC

ii
Primer: S7-300 Programmable Controller, Quick Start
C79000 G7076 C500 01
This manual contains notices which you should observe to ensure your own personal safety, as well asto
protect the product and connected equipment. These notices are highlighted in the manual by a warning
triangle and are marked as follows according to the level of danger:
!Danger
indicatesthatdeath,severepersonalinjuryorsubstantialpropertydamagewillresultifproperprecautionsare
not taken.
!Warning
indicatesthatdeath,severepersonalinjuryorsubstantialpropertydamagecanresultifproperprecautionsare
not taken.
!Caution
indicates that minor personal injury or property damage can result if proper precautions are not taken.
Note
drawsyourattentiontoparticularlyimportantinformationontheproduct,handlingtheproduct,ortoaparticular
part of the documentation.
The device/system may only be set up and operated in conjunction with this manual.
Only qualified personnel should be allowed to install and work on this equipment. Qualified persons are
defined as persons who are authorized to commission, to ground, and to tag circuits, equipment, and sys-
tems in accordance with established safety practices and standards.
Note the following:
!Warning
Thisdeviceanditscomponentsmayonlybeusedfortheapplicationsdescribedinthecatalogorthetechnical
description, and onlyinconnectionwith devicesor components fromother manufacturers whichhave been
approved or recommended by Siemens.
Thisproductcanonlyfunctioncorrectlyandsafelyifitistransported,stored,setup,andinstalledcorrectly,and
operated and maintained as recommended.
SIMATICRand SINECRare registered trademarks of SIEMENS AG.
Third parties using for their own purposes any other names in this document which refer to
trademarks might infringe upon the rights of the trademark owners.
We have checked the contents of this manual for agreement with the
hardwareandsoftwaredescribed.Sincedeviationscannotbeprecluded
entirely, we cannot guarantee full agreement. However, the data in this
manualarereviewedregularlyandanynecessarycorrectionsincludedin
subsequent editions. Suggestions for improvement are welcomed.
Technical data subject to change.
ESiemens AG 1996
Disclaimer of LiabilityCopyright ESiemens AG 1996 All rights reserved
Thereproduction,transmissionoruseofthisdocumentoritscontentsis
notpermittedwithoutexpresswrittenauthority.Offenderswillbeliablefor
damages.Allrights,includingrightscreatedbypatentgrantorregistration
of a utility model or design, are reserved.
Siemens AG
AutomationGroup
IndustrialAutomation Systems
Postfach4848, D-90327Nürnberg
Siemens Aktiengesellschaft C79000-G7076-C500
Safety Guidelines
Qualified Personnel
Correct Usage
Trademarks

iii
Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
Preface to the Primer
Hold on there. You weren’t going
to continue without reading the
Preface, were you?
The Preface gives you an overview of the information contained in the Primer.

iv Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
With this Primer, we aim to show you how easily you can install the S7-300
programmable logic controller and program it with the relevant STEP 7
programming software.
The Primer supports you with:
SSimple step-by-step instructions and
SAn easily understandable sample program that leads you through the
entire programming procedure and which can be used as a basis for your
own program.
If you have not yet had any experience with our SIMATIC programmable
controllers, this Primer will provide you with the information you need as a
first-time user.
The form and content of the Primer are such that you can work through it
chapter by chapter.
The individual chapters describe what you have to do in chronological order.
Our intention here is to provide you with a ‘connecting thread’ that you can
follow when installing and programming your S7-300 programmable
controller.
The following page gives you an overview of the contents of the individual
chapters to help you find your way around the Primer.
First, here’s an overview before
you start working with the
Primer!
Aims of the Primer
Structure of the
Primer
Preface to the Primer
What Does This Primer Describe?

v
Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
The individual chapters of the Primer provide you with the following
information and procedures:
SChapter 1: Requirements for Working with the Primer
This chapter lists the hardware and software requirements for working
with the Primer.
SChapter 2: Defining and Structuring the Control Task
Using the TLIGHT sample program, we show how you can design a
program for a specific control task and how the program is then executed
by your programmable controller.
SChapter 3: Installing and Wiring Your S7-300
In this chapter, we explain the minimum components required to make up
an S7-300 and how you can install and wire your S7-300 and connect it to
a programming device or PC.
SChapter 4: Working with the STEP 7 Programming Software
Here, you learn how to use the STEP 7 programming software. In
addition, you are also introduced to the STEP 7 objects with which you
will work.
SChapter 5: Configuring and Assigning Parameters to Your S7-300
This chapter tells you how you can configure and assign parameters to
your S7-300 in order to adapt it to your requirements.
SChapter 6: Programming Logic Blocks with STEP 7
This chapter contains examples for programming in the STEP 7
languages STL (statement list), LAD (ladder logic), and FBD (function
block diagram).
SChapter 7: Downloading and Testing Your User Program
Finally, we show you how to proceed when you want to download your
user program to the CPU and test it.
What Does Each
Chapter Contain?
Chap.1
Chap.2
Chap.3
Chap.4
Chap.5
Chap.6
Chap.7
Preface to the Primer

vi Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
Preface to the Primer

vii
Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
Contents
Preface to the Primer iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Requirements for Working with the Primer 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hardware Requirements 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Software Requirements 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other References for This Chapter 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Defining and Structuring the Control Task 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Design a Control Task? 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Define and Structure Your Control Task 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other References for This Chapter 2-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Installing and Wiring Your S7-300 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What Do You Need to Know Before you Start? 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Install Your S7-300? 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Wire Your S7-300? 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Connect Your Programming Device/PC? 3-6. . . . . . . . . . . . . . . . . . . . . . . . .
Other References for This Chapter 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Working with the STEP 7 Programming Software 4-1. . . . . . . . . . . . . . . . . . . . . . . . . .
What is STEP 7? 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Work with STEP 7? 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Which STEP 7 Objects Should You Know? 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
This is How You Create a Project Structure! 4-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other References for This Chapter 4-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Configuring and Assigning Parameters to Your S7-300 5-1. . . . . . . . . . . . . . . . . . . . .
What is Configuring and Assigning Parameters? 5-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Configure and Assign 5-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
First Perform a Memory Reset of Your CPU! 5-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Configure and Assign Parameters to Your S7-300? 5-5. . . . . . . . . . . . . . . .
What Does a Configuration Table Look Like? 5-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other References for This Chapter 5-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

viii Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
6 Programming Logic Blocks with STEP 7 6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Procedure for Programming Blocks 6-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Create the Required Blocks? 6-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What are STL, LAD, and FBD? 6-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Program Blocks in STL? 6-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Program Blocks in LAD? 6-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Program Blocks in FBD? 6-14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other References for This Chapter 6-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7 Downloading and Testing Your User Program 7-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Procedure for Downloading and Testing 7-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Download the User Program to Your S7-300? 7-3. . . . . . . . . . . . . . . . . . . .
What Do You Have to Know about Testing? 7-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Test Your STL Program? 7-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Test Your LAD Program? 7-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Do You Test Your FBD Program? 7-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other References for This Chapter 7-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glossary
Index
Contents

1-1
Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
Requirements for Working with the Primer
You mean to say,
this is all you need for working
with the Primer?
We have made every effort to keep the hardware and software requirements for working with
the Primer to a minimum.
1

1-2 Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
For working with the Primer and executing the TLIGHT sample program,
you require the following hardware components:
Component Function Illustration
Rail ... functions as a mounting rack for
an S7-300.
Power supply module (PS) ... converts the supply voltage
(120/230 VAC) to 24 VDC operating
voltage for supplying the S7-300.
CPU (central processing unit)
Backup battery (optional)
... executes the user program;
supplies the S7-300 backplane bus
with 5 V; communicates via the MPI
(multipoint interface) with other
CPUs, or with a programming
device/PC.
Simulator module (6ES7 374...) with
8 digital inputs and 8 digital outputs ... gives you the option of testing the user program on startup and during
operation by simulating sensor
signals via switches and displaying
signal states at the outputs via LEDs.
MPI cable ... connects a programming
device/PC with a CPU.
Programming device (PG) with an
MPI module and pre-installed
STEP 7 software
or
... configures, assigns parameters,
programs, and tests the S7-300
programmable controller.
Personal computer (PC) with an MPI
module or PC/MPI cable with
pre-installed STEP 7 software
... configures, assigns parameters,
programs, and tests the S7-300
programmable controller.
What Hardware Do
You Need?
Requirements for Working with the Primer
Hardware Requirements

1-3
Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
For working with the Primer and executing the TLIGHT sample program,
you require:
SWINDOWS 95 and
SThe STEP 7 software package, version 3.
STEP 7 contains a SETUP program that carries out the installation
automatically.
On-screen prompts lead you step-by-step through the entire installation
process.
What Software Do
You Need?
STEP 7 Software
Package
Requirements for Working with the Primer
Software Requirements
Please note
To work with the Primer, we assume you have already
installed the STEP 7 software package.
If you have an older version of STEP 7, you must install the
new version (see above) of our STEP 7 software.

1-4 Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
If you still have questions and you need additional information regarding
hardware and software requirements, our manuals may be of assistance.
Anything you can’t find in our
manuals, you will find in the
online help for STEP 7!
You Will Find Information on... In...
the hardware requirements for working with STEP 7
S7-300 Programmable Controller,
Hardware and Installation
and
S7-300, M7-300 Programmable Controller,
Module Specifications
the following manuals:
installing the STEP 7 software
Standard Software for S7 and M7
STEP 7
the following manual:
Where Can You
Find Other
References?
Requirements for Working with the Primer
Other References for This Chapter

2-1
Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
Defining and Structuring the Control Task
We will show you exactly how to implement a simple control system using the TLIGHT
sample program.
Your control task in the
Primer is to design a TLIGHT
control system.
2

2-2 Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
Using the TLIGHT sample program, we intend to show you step-by-step how
to proceed in designing a control task. You can then transfer this procedure to
your own applications.
Figure 2-1 shows you an overview of the procedure with the help of a few
questions:
What is to be controlled?
What subtasks are to be performed?
What safety requirements apply?
What other requirements apply?
Which addresses do you need?
Defining and structuring your control task
Figure 2-1 Defining and Structuring a Control Task
On the following pages, we will
show you how you can answer the
above questions and then design
your control task.
Basic Procedure
Defining and Structuring the Control Task
How Do You Design a Control Task?

2-3
Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
The TLIGHT sample program to be created will control vehicle and
pedestrian traffic at a pedestrian crossing, as shown in Figure 2-2.
The TLIGHT program is to control both
SThe traffic lights for vehicle traffic (traffic lights) and
SThe traffic lights for pedestrian traffic (pedestrian lights).
The traffic lights are equipped with the usual red, yellow, and green signals.
The pedestrian lights each have a green and red signal as well as a
pushbutton for pedestrians to request green.
Figure 2-2 The TLIGHT Sample Program is to Control Traffic at a Pedestrian Crossing as Shown
What is to be
Controlled?
What Subtasks are
to be Performed?
Defining and Structuring the Control Task
How to Define and Structure Your Control Task

2-4 Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
You must take into account the following safety requirements in order to
prevent any hazard to pedestrians or drivers:
SThe default setting should be green for the traffic light and red for the
pedestrian light, in order to define a safe starting point.
SIf the program receives a request to change the pedestrian light to green
as a result of the pushbutton being pressed, the traffic light changes from
green to red via yellow, as shown in Figure 2-3.
Apart from the safety requirements, you must now define how long the
individual signal phases are to last and when they are to start:
SThe yellow phase for vehicle traffic is to last 3 seconds.
SThe red phase for vehicle traffic is to last 16 seconds and it is to start
simultaneously with the green phase for pedestrians.
SThe green phase for pedestrians is to last 10 seconds.
SAs soon as the green phase for pedestrians has finished, the pedestrian
signal is to change to red.
SThe red/yellow phase for vehicle traffic is to last 3 seconds.
SThe delay for the next green request for pedestrians is to last 1 second.
Figure 2-3 gives you a schematic overview of how the TLIGHT sample
program should work:
Red for pedestrian lights
Vehicle lights switch from green
Request for green for
pedestrian lights.
Pedestrian lights switch to green
Default setting
Green for vehicle lights
Vehicle lights switch after delay
of 6 s from red via yellow
(3 s) to green.
and back to red after 10 s.
to red (16 s).
via yellow (2 s)
Delay for next green request (1 s).
Figure 2-3 Schematic Overview of the Traffic Light Control Sequence
What Safety
Requirements
Apply?
What Other
Requirements
Apply?
Defining and Structuring the Control Task

2-5
Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
In order for the TLIGHT sample program to simulate a traffic light control
system on the simulator module of your S7-300, you must define the
following addresses to which you can also assign a symbolic name:
S2 inputs (I) for requesting green for the pedestrians on both sides of the
street.
S5 outputs (Q) for controlling the signal indicators of both sets of lights.
S1 memory bit (M) for switching the signal after a green request from a
pedestrian.
S5 timers (T) to determine the duration of each signal phase. The timers
each have the S5Time format.
I 0.0 and I 0.1
Q 0.5
Q 0.6
Q 0.7
Pedestrian light Vehicle light
Q 0.0
Q 0.1
Figure 2-4 Traffic Light Indicators and the Required Inputs and Outputs
Address Description Example of Symbolic
Names
Q 0.0
Q 0.1
Q 0.5
Q 0.6
Q 0.7
Red for pedestrians
Green for pedestrians
Red for vehicles
Yellow for vehicles
Green for vehicles
Ped_Red
Ped_Green
Veh_Red
Veh_Yel
Veh_Green
I 0.0
I 0.1 Pushbutton on right-hand side of street Pushbutton on left-hand side of street Pushb_Right Pushb_Left
M 0.0 Memory bit for switching the signal
after a green request from a pedestrian Signal_Mem
T 2
T 3
T 4
T 5
T 6
Duration of yellow phase for vehicles
Duration of green phase for pedestrians
Delay red phase for vehicles
Duration of red/yellow phase for
vehicles
Delay next green request for pedestrians
Veh_Yel_Phase
Ped_Green_Phase
Veh_Del_Red
Veh_Red_Yel_Phase
Ped_Del_Green
Which Addresses
Do You Need?
Defining and Structuring the Control Task

2-6 Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
If input I 0.0 or I 0.1 is set by the pedestrian green request, the following
occurs:
SThe traffic light switches from Q 0.7 (green) via Q 0.6 (yellow) to Q 0.5
(red) and
SThe pedestrian light switches from Q 0.0 (red) to Q 0.1 (green)
The outputs are set alternately by the timers defined in the program.
Figure 2-5 shows the signal states of the inputs and outputs during the
TLIGHT sample program sequence:
Signalstates
Q 0.5: Veh_Red
Q 0.6: Veh_Yel
2 6 10 12 14 16 18 20 22 24 26 28
Vehicle lights
Pedestrian lights
84300
Q 0.1: Ped_Green
Time in s
I 0.0 or I 0.1:
Switch right or left
Q 0.7: Veh_Green
Q 0.0: Ped_Red
0 = off
1 = on
1
0
1
0
1
0
1
0
1
0
1
0
Figure 2-5 Signal States of the Inputs and Outputs During the TLIGHT Sample Program Sequence
Sample Program
Sequence
Defining and Structuring the Control Task

2-7
Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
If you still have questions and you need additional information with regard to
defining and structuring your own control task, our manuals may be of
assistance.
You will find a detailed example
in the manual below!
You Will Find Information on... In...
defining and structuring a control task and on overall
program design for your S7-300
System Software for S7-300 and S7-400
Program Design
the following manual:
Where Can You
Find Other
References?
Defining and Structuring the Control Task
Other References for This Chapter

2-8 Primer: S7-300 Programmable Controller, Quick Start
C79000-G7076-C500-01
Defining and Structuring the Control Task