Mitsubishi MELSEC System Q User manual

MELSEC System Q
Programmable Logic Controllers
Beginner´s Manual
MITSUBISHI ELECTRIC
Art. no.: 209093
29082007
Version A
INDUSTRIAL AUTOMATION
MITSUBISHI ELECTRIC

The texts, illustration, diagrams and examples in this manual are provided
for information purposes only. They are intended as aids to help explain the
installation, operation, programming and use of the
programmable logic controllers of the MELSEC System Q.
If you have any questions about the installation and operation of any of the
products described in this manual please contact your local sales office or distributor (see back cover).
You can find the latest information and answers to frequently asked questions on our website at
www.mitsubishi-automation.com .
MITSUBISHI ELECTRIC EUROPE BV reserves the right to make changes
to this manual or the technical specifications of its products at any time without notice.
© 08/2007

Beginner’s Manual for the programmable logic controllers of the
MELSEC System Q
Art. no.: 209093
Version Revisions / Additions / Corrections
A 08/2007 pdp-dk First edition

Safety Guidelines
For use by qualified staff only
This manual is only intended for use by properly trained and qualified electrical technicians
who are fully acquainted with the relevant automation technology safety standards. All work
with the hardware described, including system design, installation, configuration, mainte-
nance, service and testing of the equipment, may only be performed by trained electrical tech-
nicians with approved qualifications who are fully acquainted with all the applicable automa-
tion technology safety standards and regulations. Any operations or modifications to the
hardware and/or software of our products not specifically described in this manual may only be
performed by authorised Mitsubishi Electric staff.
Proper use of the products
The programmable logic controllers of the MELSEC System Q are only intended for the spe-
cific applications explicitly described in this manual. All parameters and settings specified in
this manual must be observed. The products described have all been designed, manufac-
tured, tested and documented in strict compliance with the relevant safety standards. Unquali-
fied modification of the hardware or software or failure to observe the warnings on the products
and in this manual may result in serious personal injury and/or damage to property. Only
peripherals and expansion equipment specifically recommended and approved by Mitsubishi
Electric may be used with the programmable logic controllers of the MELSEC System Q.
All and any other uses or application of the products shall be deemed to be improper.
Relevant safety regulations
All safety and accident prevention regulations relevant to your specific application must be
observed in the system design, installation, configuration, maintenance, servicing and testing
of these products. The regulations listed below are particularly important in this regard. This
list does not claim to be complete, however; you are responsible for being familiar with and
conforming to the regulations applicable to you in your location.
쎲VDE Standards
–VDE 0100
Regulations for the erection of power installations with rated voltages below 1000 V
–VDE 0105
Operation of power installations
–VDE 0113
Electrical installations with electronic equipment
–VDE 0160
Electronic equipment for use in power installations
–VDE 0550/0551
Regulations for transformers
–VDE 0700
Safety of electrical appliances for household use and similar applications
–VDE 0860
Safety regulations for mains-powered electronic appliances and their accessories for
household use and similar applications.
쎲Fire safety regulations
MELSEC System Q Beginners Manual I
Safety Guidelines

쎲Accident prevention regulations
–VBG Nr.4
Electrical systems and equipment
Safety warnings in this manual
In this manual warnings that are relevant for safety are identified as follows:
PDANGER:
Failure to observe the safety warnings identified with this symbol can result in health
and injury hazards for the user.
EWARNING:
Failure to observe the safety warnings identified with this symbol can result in damage
to the equipment or other property.
II MITSUBISHI ELECTRIC
Safety Guidelines

General safety information and precautions
The following safety precautions are intended as a general guideline for using PLC systems
together with other equipment. These precautions must always be observed in the design,
installation and operation of all control systems.
P
DANGER
MELSEC System Q Beginners Manual III
Safety Guidelines
쎲
Observe all safety and accident prevention regulations applicable to your spe-
cific application. Always disconnect all power supplies before performing
installation and wiring work or opening any of the assemblies, components and
devices.
쎲
Assemblies, components and devices must always be installed in a shockproof
housing fitted with a proper cover and fuses or circuit breakers.
쎲
Devices with a permanent connection to the mains power supply must be inte-
grated in the building installations with an all-pole disconnection switch and a
suitable fuse.
쎲
Check power cables and lines connected to the equipment regularly for breaks
and insulation damage. If cable damage is found immediately disconnect the
equipment and the cables from the power supply and replace the defective
cabling.
쎲
Before using the equipment for the first time check that the power supply rating
matches that of the local mains power.
쎲
Take appropriate steps to ensure that cable damage or core breaks in the signal
lines cannot cause undefined states in the equipment.
쎲
You are responsible for taking the necessary precautions to ensure that pro-
grams interrupted by brownouts and power failures can be restarted properly
and safely. In particular, you must ensure that dangerous conditions cannot
occur under any circumstances, even for brief periods.
쎲
EMERGENCY OFF facilities conforming to EN 60204/IEC 204 and VDE 0113
must remain fully operative at all times and in all PLC operating modes. The
EMERGENCY OFF facility reset function must be designed so that it cannot
ever cause an uncontrolled or undefined restart.
쎲
You must implement both hardware and software safety precautions to prevent
the possibility of undefined control system states caused by signal line cable or
core breaks.
쎲
When using modules always ensure that all electrical and mechanical specifi-
cations and requirements are observed exactly.

IV MITSUBISHI ELECTRIC
Safety Guidelines

MELSEC System Q Beginners Manual V
Contents
Contents
1 Introduction
1.1 About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
1.2 More Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
2 Programmable Logic Controllers
2.1 What is a PLC? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
2.2 How PLCs Process Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
3 The MELSEC System Q
3.1 System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
3.2 Base Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
3.2.1 Extensions Base Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
3.2.2 Allocation of I/O Addresses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
3.3 Power Supply Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5
3.4 The CPU Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
3.4.1 Part Names of CPU Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9
3.4.2 Memory Organisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-12
3.4.3 Installation of the Battery for the CPU Module . . . . . . . . . . . . . . . . . . . . 3-15
3.5 Digital Input and Output Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-16
3.5.1 Digital Input Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17
3.5.2 Digital Output Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-24
3.6 Special Function Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-31
3.6.1 Analog Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-31
3.6.2 Temperature Control Modules with PID Algorithm . . . . . . . . . . . . . . . . . 3-34
3.6.3 High-Speed Counter Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
3.6.4 Positioning Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-35
3.6.5 Serial Communication Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-35
3.6.6 BASIC Programmable Interface Modules . . . . . . . . . . . . . . . . . . . . . . . . 3-36

VI MITSUBISHI ELECTRIC
Contents
3.7 Networks and Network Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-37
3.7.1 Networking on all Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-37
3.7.2 Open Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-38
3.7.3 MELSEC Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-40
3.7.4 Network Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-41
4 An Introduction to Programming
4.1 Structure of a Program Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
4.2 Bits, Bytes and Words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
4.3 Number Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
4.4 Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5
4.4.1 BCD Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5
4.4.2 ASCII Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6
4.5 Programming Languages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7
4.5.1 Text Editors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7
4.5.2 Graphic Editors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
4.6 The IEC 61131-3 Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-10
4.6.1 Software Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-10
4.6.2 Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11
4.7 The Basic Instruction Set. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-13
4.7.1 Starting logic operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-14
4.7.2 Outputting the result of a logic operation . . . . . . . . . . . . . . . . . . . . . . . . 4-14
4.7.3 Using switches and sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-16
4.7.4 AND operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-17
4.7.5 OR operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-18
4.7.6 Instructions for connecting operation blocks . . . . . . . . . . . . . . . . . . . . . 4-20
4.7.7 Pulse-triggered execution of operations . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
4.7.8 Setting and resetting devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-25
4.7.9 Generating pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-28
4.7.10 Inverting the result of an operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29
4.7.11 Inversion of bit output device. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-30
4.7.12 Operation result into pulse conversion . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31
4.8 Safety First! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-32

MELSEC System Q Beginners Manual VII
Contents
4.9 Programming PLC Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-34
4.9.1 A rolling shutter gate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-34
4.9.2 Programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-35
4.9.3 The Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-46
5 Devices in Detail
5.1 Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
5.1.1 External I/O Signals and I/O Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
5.1.2 Inputs and Outputs of the MELSEC System Q . . . . . . . . . . . . . . . . . . . . . 5-3
5.2 Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
5.2.1 Special relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-5
5.3 Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-6
5.4 Counters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-9
5.5 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-11
5.5.1 Data registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-11
5.5.2 Special registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-12
5.5.3 File registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-13
5.6 Constants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-14
5.6.1 Decimal and Hexadecimal constants . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
5.6.2 Floating decimal point constants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
5.6.3 Character string constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-14
5.7 Programming Tips for Timers and Counters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
5.7.1 Specifying timer and counter setpoints indirectly . . . . . . . . . . . . . . . . . . 5-15
5.7.2 Switch-off delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-17
5.7.3 Delayed make and break . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-19
5.7.4 Clock signal generators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-20
6 More Advanced Programming
6.1 Applied Instructions Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1
6.1.1 Additional Instructions for Process CPUs . . . . . . . . . . . . . . . . . . . . . . . . 6-10
6.2 Instructions for Moving Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-12
6.2.1 Moving individual values with the MOV instruction . . . . . . . . . . . . . . . . . 6-12
6.2.2 Moving groups of bit devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-14
6.2.3 Moving blocks of data with the BMOV instruction . . . . . . . . . . . . . . . . . . 6-16
6.2.4 Copying source devices to multiple destinations (FMOV). . . . . . . . . . . . 6-17
6.2.5 Exchanging data with special function modules . . . . . . . . . . . . . . . . . . . 6-18

VIII MITSUBISHI ELECTRIC
Contents
6.3 Compare Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-22
6.4 Math Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-25
6.4.1 Addition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-25
6.4.2 Subtraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-28
6.4.3 Multiplication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-29
6.4.4 Division . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-30
6.4.5 Combining math instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-31
Index

1 Introduction
1.1 About this Manual
This manual will help you to familiarise yourself with the use of the programmable logic control-
lers of the MELSEC System Q .It is designed for users who do not yet have any experience with
programming programmable logic controllers (PLCs).
Programmers who already have experience with PLCs from other manufacturers can also use
this manual as a guide for making the transition to the MELSEC System Q.
1.2 More Information
You can find more detailed information on the individual products in the MELSEC System Q in
the operating and installation manuals of the individual modules.
See the MELSEC System Q Technical Catalogue, art. no.136731, for a general overview of all
the controllers in the MELSEC System Q. This catalogue also contains information on special
function modules and the available accessories.
The communications capabilities using MELSEC or open networks like Ethernet or Profibus
are documented in detail in the Technical Catalogue Networks, art. no. 136730.
The Hardware Manuals of the MELSEC System Q support you when designing a controller
system and also during installation and start-up of the PLC.
For an introduction to using the programming software package see the GX IEC Developer
Beginner’s Manual, art. no. 043596 and the Reference Manual, art. no. 043597.
You can find detailed documentation of all programming instructions in the Programming Man-
ual for the MELSEC A/Q Series and the MELSEC System Q, art. no. 87431. Additional pro-
gram examples are given in almost all manuals for special function modules.
NOTE All Mitsubishi manuals and catalogues can be downloaded free of charge from the
Mitsubishi website at
www.mitsubishi-automation.com .
MELSEC System Q Beginners Manual 1 – 1
Introduction About this Manual

1–2 MITSUBISHI ELECTRIC
More Information Introduction

2 Programmable Logic Controllers
2.1 What is a PLC?
In contrast to conventional controllers with functions determined by their physical wiring the
functions of programmable logic controllers or PLCs are defined by a program.PLCs also have
to be connected to the outside world with cables, but the contents of their program memory can
be changed at any time to adapt their programs to different control tasks.
Programmable logic controllers input data, process it and then output the results. This process
is performed in three stages:
쎲an input stage,
쎲a processing stage
and
쎲an output stage
The input stage
The input stage passes control signals from switches, buttons or sensors on to the processing
stage.
The signals from these components are generated as part of the control process and are fed to
the inputs as logical states. The input stage passes them on to the processing stage in a
pre-processed format.
The processing stage
In the processing stage the pre-processed signals from the input stage are processed and
combined with the help of logical operations and other functions. The program memory of the
processing stage is fully programmable.The processing sequence can be changed at any time
by modifying or replacing the stored program.
The output stage
The results of the processing of the input signals by the program are fed to the output stage
where they control connected switchable elements such as contactors, signal lamps, solenoid
valves and so on.
MELSEC System Q Beginners Manual 2 – 1
Programmable Logic Controllers What is a PLC?
Programmable Logic Controller
Input Stage Output Stage
Processing Stage
Contactors
Switch
Input Output

2.2 How PLCs Process Programs
A PLC performs its tasks by executing a program that is usually developed outside the control-
ler and then transferred to the controller’s program memory. Before you start programming it is
useful to have a basic understanding of how PLCs process these programs.
A PLC program consists of a sequence of instructions that control the functions of the control-
ler. The PLC executes these control instructions sequentially, i.e. one after another. The entire
program sequence is cyclical, which means that it is repeated in a continuous loop. The time
required for one program repetition is referred to as the program cycle time or period.
Process image processing
The program in the PLC is not executed directly on the inputs and outputs, but on a “process
image” of the inputs and outputs:
Input process image
At the beginning of each program cycle the system polls the signal states of the inputs and
stores them in a buffer, creating a “process image” of the inputs.
2–2 MITSUBISHI ELECTRIC
How PLCs Process Programs Programmable Logic Controllers
....
....
....
Switch on PLC
Delete output memory
Input terminals
Process image
of inputs
PLC program
Process image
of outputs
Output terminals Transfer process image
to outputs
Instruction 1
Instruction 2
Instruction 3
Instruction n
Poll inputs and signal states
and save them in the process
image of the inputs
Input signals
Output signals

Program execution
After this the program is executed, during which the PLC accesses the stored states of the
inputs in the process image. This means that any subsequent changes in the input states will
not be registered until the next program cycle!
The program is executed from top to bottom, in the order in which the instructions were pro-
grammed.Results of individual programming steps are stored and can be used during the cur-
rent program cycle.
Output process image
Results of logical operations that are relevant for the outputs are stored in an output buffer – the
output process image.The output process image is stored in the output buffer until the buffer is
rewritten. After the values have been written to the outputs the program cycle is repeated.
Differences between signal processing in the PLC and in hard-wired controllers
In hard-wired controllers the program is defined by the functional elements and their connec-
tions (the wiring). All control operations are performed simultaneously (parallel execution).
Every change in an input signal state causes an instantaneous change in the corresponding
output signal state.
In a PLC it is not possible to respond to changes in input signal states until the next program
cycle after the change. Nowadays this disadvantage is largely compensated by very short pro-
gram cycle periods.The duration of the program cycle period depends on the number and type
of instructions executed.
MELSEC System Q Beginners Manual 2 – 3
Programmable Logic Controllers How PLCs Process Programs
M6
M2
M1 M8013
4
X000 X001
0
9
M0
Y000
M0
Y001
Store result
Program execution
Process stored result
Control output

2–4 MITSUBISHI ELECTRIC
How PLCs Process Programs Programmable Logic Controllers