L_Series_GXWorks2_Programming_RevA.

L_Series_GXWorks2_Programming_RevA.
L Series Programming (GX Works2)
TRPLC701P
L Series Programming (GX Works2) Training Manual
MEAU Manual Number R72-106-SLSASG-001
Revision History
Rev.
*
A
Date
06/02/2010
C. Kellock
06/29/2010
C. Kellock
Revision Notes
Internal, created in part from existing Q Series Programming (GX
Works2) and iQ Works Structured Programming training manuals
First public release version
Disclaimer
This manual does not imply guarantee or implementation right for industrial ownership
or implementation of other rights. Mitsubishi Electric is not responsible for industrial
ownership problems caused by use or misuse of the contents of this manual.
© 2010 Mitsubishi Electric Automation, Inc.
i
ii
Table of Contents
Class Introduction......................................................................................1
Course Objectives ....................................................................................................... 1
Prerequisites................................................................................................................ 1
Course Duration .......................................................................................................... 1
Course Description ...................................................................................................... 2
List of Relevant Manuals ............................................................................................. 3
LESSON 1 – Hardware Review..................................................................5
Lesson Objectives ....................................................................................................... 5
1.1
Power Supplies ................................................................................................. 5
1.2
CPUs ................................................................................................................ 6
1.3
Memory Drives.................................................................................................. 9
1.4
Discrete I/O ..................................................................................................... 10
1.5
Intelligent Function Modules ........................................................................... 12
1.6
Accessories..................................................................................................... 14
1.7
Overall System Configuration ......................................................................... 15
LESSON 2 – Controller Basics................................................................17
Lesson Objectives ..................................................................................................... 17
2.1
Memory Areas................................................................................................. 17
2.1.1
Discrete I/O (X/Y)..................................................................................... 17
2.1.2
Memory Bits (M/L) ................................................................................... 17
2.1.3
Data Registers (D) ................................................................................... 17
2.1.4
Timers and Counters (T/ST/C)................................................................. 18
2.1.5
Fault Annunciators (F) ............................................................................. 18
2.1.6
Step Relays (S)........................................................................................ 19
2.1.7
File Registers (R)..................................................................................... 19
2.1.8
Index Registers (Z) .................................................................................. 20
2.2
Constants........................................................................................................ 20
2.3
System Addressing ......................................................................................... 21
2.4
EXERCISE – Addressing ................................................................................ 22
2.5
Ladder Review ................................................................................................ 23
2.6
Timers ............................................................................................................. 24
2.7
Timer Examples .............................................................................................. 27
2.8
Counters ......................................................................................................... 29
2.9
Counter Examples .......................................................................................... 30
iii
LESSON 3 – GX Works2 Introduction ....................................................31
Lesson Objectives ..................................................................................................... 31
3.1
GX Works2 New and Improved Features ....................................................... 31
3.2
Backward Compatibility................................................................................... 32
3.3
File Format...................................................................................................... 33
3.4
Compress/Unpack .......................................................................................... 34
3.5
Launching GX Works2 .................................................................................... 35
3.6
Docking Windows ........................................................................................... 36
3.7
Toolbars .......................................................................................................... 39
3.8
Customizing the Keyboard .............................................................................. 40
3.9
Status Bar ....................................................................................................... 41
3.10 Software Options ............................................................................................ 42
LESSON 4 – Creating a Project...............................................................43
Lesson Objectives ..................................................................................................... 43
4.1
Simple vs. Structured Project.......................................................................... 43
4.2
Creating a New Project ................................................................................... 44
4.3
Editing Ladder Logic ....................................................................................... 45
4.4
EXERCISE – Basic Ladder Logic ................................................................... 46
4.5
Connection Setup ........................................................................................... 47
4.6
Transferring to the PLC................................................................................... 49
4.7
Reading from the PLC .................................................................................... 52
4.8
Verify with PLC ............................................................................................... 53
LESSON 5 – Online Operations ..............................................................55
Lesson Objectives ..................................................................................................... 55
5.1
Ladder Logic Monitor ...................................................................................... 55
5.2
Device / Buffer Memory Batch Monitor ........................................................... 57
5.3
Watch Windows .............................................................................................. 59
5.4
Intelligent Module Monitor ............................................................................... 60
5.5
Online Edits..................................................................................................... 61
5.6
Modify Value ................................................................................................... 63
5.7
Forced I/O Registration ................................................................................... 64
iv
LESSON 6 – GX Works2 Utilities ............................................................67
Lesson Objectives ..................................................................................................... 67
6.1
Find/Replace Menu......................................................................................... 67
6.2
Cross Reference ............................................................................................. 76
6.3
Device List ...................................................................................................... 77
6.4
PLC Diagnostics ............................................................................................. 78
6.5
System Monitor ............................................................................................... 82
6.5.1
Module Detailed Information .................................................................... 83
6.5.2
Product Information List ........................................................................... 86
6.6
Sampling Trace............................................................................................... 87
6.7
EXERCISE – Sampling Trace......................................................................... 92
LESSON 7 – Special Addresses .............................................................93
Lesson Objectives ..................................................................................................... 93
7.1
Special Memory Bits ....................................................................................... 93
7.2
Special Registers ............................................................................................ 95
7.3
Troubleshooting Examples.............................................................................. 97
7.3.1
Battery Low Warning Indicator................................................................. 97
7.3.2
PLC Error Code Backup .......................................................................... 97
7.4
Real Time Clock.............................................................................................. 98
LESSON 8 – Intelligent Modules.............................................................99
Lesson Objectives ..................................................................................................... 99
8.1
Intelligent Module Introduction ........................................................................ 99
8.2
TO/FROM Instructions .................................................................................. 101
8.3
U\G Addresses.............................................................................................. 104
8.4
Intelligent Function Utility .............................................................................. 105
8.5
EXERCISE – Intelligent Module Access ....................................................... 110
LESSON 9 – PLC Parameters................................................................111
Lesson Objectives ................................................................................................... 111
9.1
PLC Parameters ........................................................................................... 111
9.2
PLC Name .................................................................................................... 112
9.3
PLC System .................................................................................................. 113
9.4
PLC File ........................................................................................................ 115
9.5
PLC RAS....................................................................................................... 116
9.6
Boot file ......................................................................................................... 117
9.7
Program ........................................................................................................ 118
9.8
SFC............................................................................................................... 118
9.9
Device ........................................................................................................... 119
9.10 I/O Assignment ............................................................................................. 121
9.11 Built-In Ethernet ............................................................................................ 124
9.12 Built-In I/O Functions .................................................................................... 125
9.13 Network Parameters ..................................................................................... 126
v
LESSON 10 – Label Programming........................................................127
Lesson Objectives ................................................................................................... 127
10.1 What are Labels?.......................................................................................... 127
10.2 Registering Global Labels ............................................................................. 129
10.3 Registering Local Labels............................................................................... 131
10.4 Automatic Assignment .................................................................................. 132
10.5 Using Labels ................................................................................................. 133
10.6 EXERCISE – Global Labels .......................................................................... 134
LESSON 11 – Structured Projects ........................................................135
Lesson Objectives ................................................................................................... 135
11.1 IEC 61131-3.................................................................................................. 135
11.2 IEC Addresses .............................................................................................. 137
11.3 Structured Project ......................................................................................... 140
11.4 Program Organization Unit............................................................................ 141
11.5 Tasks ............................................................................................................ 143
11.6 Programs ...................................................................................................... 145
11.7 Compiling the Program ................................................................................. 146
11.8 Symbolic Information .................................................................................... 147
11.9 EXERCISE – Structured Project ................................................................... 149
LESSON 12 – Structured Ladder ..........................................................151
Lesson Objectives ................................................................................................... 151
12.1 Introduction ................................................................................................... 151
12.2 Editor Basics ................................................................................................. 152
12.3 Editing Modes ............................................................................................... 154
12.4 Ladder Symbols ............................................................................................ 155
12.5 Connecting Lines .......................................................................................... 157
12.6 Functions and Function Blocks ..................................................................... 160
12.7 Constants...................................................................................................... 163
12.8 Program Documentation ............................................................................... 164
12.9 Monitoring ..................................................................................................... 165
12.10
EXERCISE – Structured Ladder................................................................ 166
12.11
Timers and Counters ................................................................................. 167
12.12
EXERCISE – Timers and Counters........................................................... 171
vi
LESSON 13 – Structured Text...............................................................173
Lesson Objectives ................................................................................................... 173
13.1 Introduction ................................................................................................... 173
13.2 Editor Basics ................................................................................................. 174
13.3 Operators ...................................................................................................... 177
13.4 Syntaxes ....................................................................................................... 177
13.5 Functions and Function Blocks ..................................................................... 183
13.6 Monitoring ..................................................................................................... 186
13.7 EXERCISE – Structured Text ....................................................................... 187
13.8 Inline Structured Text Box............................................................................. 188
13.9 EXERCISE – Inline Structured Text Box....................................................... 190
APPENDIX...............................................................................................191
APPENDIX 1 – L Series USB Driver Installation ..................................................... 193
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Class Introduction
Page 1
Class Introduction
Welcome to the L Series Programming with GX Works2 training course. This course is
intended for designers and control engineers, responsible for developing application
programs using the L Series programmable logic controllers. This class will use the GX
Works2 programming software.
Course Objectives
By the end of this training course, the student should be able to:
•
•
•
•
Identify the models of the L Series family.
Understand the system design and addressing of the L Series.
Write, download, monitor, and debug programs.
Troubleshoot and debug systems utilizing the L Series.
Prerequisites
Before attending this class, it is strongly advised that the student should attend the PLC
Basics (TRPLC003B) training class. If not attending the PLC Basics class, experience
working with PLCs from any manufacturer would be required. This class does NOT
cover the basics of PLCs.
Course Duration
This course is designed for a 3 day class length.
Class Introduction
Page 2
Course Description
LESSON 1 – Hardware Review
This lesson will introduce the various hardware components used to design an L
Series programmable controller.
LESSON 2 – Controller Basics
This lesson discusses memory areas, address allocation, and basics of ladder
logic, including timers and counters.
LESSON 3 – GX Works2 Introduction
This lesson introduces the GX Works2 programming software.
LESSON 4 – Creating a Project
This lesson discusses creating a new project and communication with the PLC.
LESSON 5 – Online Operations
This lesson will explain tools for monitoring and editing programs online.
LESSON 6 – GX Works2 Utilities
This lesson explains some of the troubleshooting tools built into GX Works2.
LESSON 7 – Special Addresses
This lesson will review the special bits and words in the PLC memory.
LESSON 8 – Intelligent Modules
This lesson explains the methods for communication with intelligent modules.
LESSON 9 – PLC Parameters
This lesson discusses the settings made in the PLC parameters.
LESSON 10 – Label Programming
This lesson discusses the use of labels instead of addresses when programming.
LESSON 11 – Structured Projects
This lesson introduces the concepts of structured programming.
LESSON 12 – Structured Ladder
This lesson demonstrates the structured ladder programming language.
LESSON 13 – Structured Text
This lesson introduces the structured text programming language.
Class Introduction
Page 3
List of Relevant Manuals
Hardware Manuals
SH(NA)080888
SH(NA)080889
SH(NA)080890
SH(NA)080891
SH(NA)080892
SH(NA)080893
L I/O Module User’s Manual
LCPU User's Manual (Function Explanation, Program Fundamentals)
LCPU User's Manual (Hardware, Design, Maintenance, Inspection)
LCPU User’s Manual (Built-In Ethernet Function)
LCPU User’s Manual (Built-In I/O Function)
LCPU User’s Manual (Data Logging Function)
Programming Manuals
SH(NA)080782
SH(NA)080783
SH(NA)080784
SH(NA)080785
SH(NA)080809
Q/L/FX Structured Programming Manual (Fundamentals)
Q/L Structured Programming Manual (Common Instructions)
Q/L Structured Programming Manual (Application Functions)
Q/L Structured Programming Manual (Special Instructions)
Q/L Programming Manual (Common Instructions)
GX Works2 Manuals
SH(NA)080779
SH(NA)080780
SH(NA)080781
SH(NA)080787
SH(NA)080788
SH(NA)080921
GX Works2 Version 1 Operating Manual (Common)
GX Works2 Version 1 Operating Manual (Simple Project)
GX Works2 Version 1 Operating Manual (Structured Project)
GX Works2 Version 1 Beginner’s Manual (Simple Project)
GX Works2 Version 1 Beginner’s Manual (Structured Project)
GX Works2 Operating Manual (Intelligent Function Module)
Page 4
LESSON 1 – Hardware Review
Page 5
LESSON 1 – Hardware Review
This lesson discusses the hardware structure of the L Series programmable controller.
This includes a review of the different CPU types, input/output modules, and intelligent
modules.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• List the modules required for an L Series control system.
• List some factors to be considered when specifying hardware.
The L Series controller is a modular PLC which does not require a backplane for
modules to communicate with the CPU. The backplane is built into the modules, and
the modules all have slide lock levers used to connect to the module before it on the
PLC. The power supply is the left-most module in the system, followed by the CPU. On
the right side of the CPU, I/O modules, network modules, and intelligent modules can
be connected. The bus is terminated with an end cover, which is included with the CPU
or CC-Link IE Field head station.
1.1
Power Supplies
The power supply module provides +5VDC power to all of
the modules that are connected to it. Each module
installed has a required current draw specification. The
total current draw of the modules should not exceed the
capability of the supply.
There are 2 basic power supplies available:
Part Number
L61P
L63P
Notes
Supply Voltage
120/240VAC
24 VDC
Bus (5VDC)
5A
5A
LESSON 1 – Hardware Review
1.2
Page 6
CPUs
The CPU module provides the processing power to the L Series controllers.
All L Series CPUs have some key built-in features. The list below details some
of the important features.
•
•
•
•
•
•
•
•
USB programming port
Ethernet communications
SD/SDHC memory card slot
16 built-in inputs, offering functions such as general input, interrupt input,
high speed counter input, pulse catch input
8 built-in outputs, offering functions such as general output or high speed
pulse positioning outputs
Built-in high speed data logging function
Location for mounting optional display module
Bus terminating end cover included with CPU module
The first processor available is the L02CPU.
The L02CPU offers control of up to 1024 I/O
points and 20K of program memory, with a
minimum instruction speed of 40ns.
Notes
LESSON 1 – Hardware Review
Page 7
The high end processor is the
L26CPU-BT, which offers up to
4096 I/O points and 260k of
program memory, with a minimum
instruction speed of 9.5ns. The
L26CPU-BT also includes built-in
CC-Link version 2 functionality.
The table below is a basic comparison of the CPU performance specifications.
Feature
Program Memory
Minimum Execution Speed
Max I/O Points
Built-In I/O Functions
Built-In Ethernet
Built-In CC-Link
Max CC-Link Networks
L02CPU
20k
40ns
1024
Yes
Yes
No
2
L26CPU-BT
260k
9.5ns
4096
Yes
Yes
Yes
4
The CPUs are also sold as a set, which includes the L61P power supply,
selected CPU, and L6DSPU display unit. These can be ordered by adding –SET
to the end of the CPU part number.
Notes
LESSON 1 – Hardware Review
An overview of the CPU hardware is shown below.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
Notes
CPU indicator lights
100M Ethernet speed light
Ethernet send/receive indicator light
Input and output indicator lights
SD memory card status light
RUN/STOP/RESET switch
SD memory card lock switch
SD memory card slot
USB connector
Ethernet port
Serial number display
Module locking levers
Display module locking lever
Battery connector
Display unit cover
Battery
I/O connector
DIN rail hook
Built-in CC-Link (L26CPU-BT only)
Page 8
LESSON 1 – Hardware Review
1.3
Page 9
Memory Drives
All L series processors have 4 memory areas referred to as drives. Each drive
can store certain components of the processor’s configuration. Drive numbers
are indicated in the table below. Drives 0, 3, and 4 are built into the CPU module.
Drive 2 is the SD memory card, if installed.
Each drive can store certain sections of the processor’s data, as shown below.
Notes
LESSON 1 – Hardware Review
1.4
Page 10
Discrete I/O
Each CPU has a total of 24 I/O points built in, using the high density 40-pin
connector on the front of the CPU.
Input and output modules in the L Series are available in a number of module
types and I/O counts. Input or output modules are available in 16, 32, or 64
points per module. Modules have either inputs or outputs.
Modules with 16 points all come with removable screw-type terminal blocks for
I/O wiring. Modules with 32 or 64 points utilize high-density connectors.
Notes
LESSON 1 – Hardware Review
Page 11
Cables and terminal blocks to connect to the high density connectors are
available, or the user can make their own cables with a field installable plug.
All high density modules use the same style 40-pin connector.
The connector options for the high density modules are shown
below.
•
•
•
A6CON1 for solder type
A6CON2 for crimp contacts
A6CON3 for flat cable
Cables which have this connector already attached at one end,
and ferrules on the loose wires at the other end, have been made
available as well. Those part numbers are shown below.
•
LCBL40P-xM where x is length in meters (2, 5, or 10)
Terminal blocks which are compatible with the high density modules are also
available. These terminal blocks are listed below. Note these terminal blocks
cannot be used with the I/O connector built into the CPU.
Cables for these terminal blocks are available in lengths from 0.5 meters to 10
meters.
Another terminal block, A6TE2-16SRN, can be used to connect to the DC output
modules, and provides individual relays for each output. Each module has 16
outputs, so the cable from the module connects to 2 of these terminal blocks.
Cables for this module are available from 0.6 meters to 10 meters.
Notes
LESSON 1 – Hardware Review
1.5
Page 12
Intelligent Function Modules
All modules which are not discrete inputs or discrete outputs are called intelligent
function modules. Some examples of intelligent modules would include analog
inputs and outputs, high speed counter, positioning, motion control, serial
communications, and networking.
All can be set up easily with built-in tools in GX Works2.
Analog Inputs and Outputs
There are 2 types of analog modules: analog input modules and analog
output modules. Both are based on varying current or voltage, usually 420 mA, 0-10V, or –10 to + 10 V, as set by the programmer.
With an input module, the actual current or voltage reading is converted
into an integer value based on the selected full scale. The analog output
modules receive an integer value from the controller, and output a voltage
or current signal based on that value.
Model
L60AD4
L60DA4
Channels
4
4
Description
Voltage or current inputs
Voltage or current outputs
High Speed Counter
Ordinary counters in the CPU are dependent on the scan time in 2 ways.
The updating of the input that is used as the counting input and the
updating of the accumulated value of the counter are part of the CPU’s
program scan. This may be too slow for high speed counting applications.
These modules provide the high speed counting ability, up to 500 KHz for
these higher speed applications.
Model
LD62
LD62D
Notes
Channels
2
2
Description
200KHz sink output
500KHz differential line driver
LESSON 1 – Hardware Review
Page 13
Positioning
These modules provide functions for the control of Servo and Inverters.
They can control multiple axes of motion, and provide functions like Scurve, acceleration/ deceleration, linear and circular interpolation, and a
variety of origin point return methods.
Different modules offer different types of servo compatibility, and motion
control capabilities.
Model
LD75P4
LD75D4
LD75MH4
Description
Open collector pulse output motion modules
Differential line driver pulse output motion
modules
Motion modules for use with MR-J3-B servos
over SSCNETIII fiber optic cable
Serial Communications
These modules provide RS-232 and RS-422 communication ports. These
modules provide connections for computers, barcode readers and other
external devices. They can be also be used to provide another
programming connection to the controller.
Model
LJ71C24N
LJ71C24N-R2
Channels
2
2
Description
(1) RS232 and (1) RS422/485
(2) RS232
Networking
Network modules provide the controller with a variety of communications
capabilities. Networks can be used to make multiple controllers
communicate with each other, to connect remote racks of modules to the
controller, or to provide remote I/O points on the network. There are
various network topologies and communication formats available.
A quick list of network modules is shown below.
Module
LJ61BT11
LJ72GF15-T2
Notes
Network
CC-Link Master/Local Module
CC-Link IE Field Head Module
LESSON 1 – Hardware Review
1.6
Page 14
Accessories
A variety of accessories exist for use with the L Series controllers. Some are
detailed below.
L6DSPU Display Unit
The L6DSPU display unit can be installed into the front of the CPU. Data in the
PLC can be monitored or adjusted via the display unit. PLC error information will
be displayed on the display module when an error is active. Using the UMSG
instruction in the PLC program, the programmer can cause text messages of
their choice to be displayed on the display module.
L6EC-ET End Cover with Error Terminal
All Q Series controllers offer an alarm output relay on the power supply module.
Since this is not built into the L Series power supply, this optional replacement
end cover includes a relay contact closure to indicate a CPU error. This end
cover installs at the right end of the PLC in place of the cover which comes with
the CPU
L6ADP-R2 RS232 Connection
The L6ADP-R2 is designed to provide the 6-pin round RS232 port, as found on
some of the Q Series processors. It is used for serial connection of a GOT to the
processor. This module installs on the left of the CPU between the processor
and the power supply.
Notes
LESSON 1 – Hardware Review
1.7
Page 15
Overall System Configuration
The diagram below shows the typical system configuration of an L02CPU based
control system.
Notes
LESSON 1 – Hardware Review
Notes
Page 16
LESSON 2 – Controller Basics
Page 17
LESSON 2 – Controller Basics
This lesson will cover the various areas of the PLC’s memory, addressing, and ladder
basics.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Identify the different areas of the PLC’s memory.
• Explain I/O addresses for an L Series control system.
• Understand basic ladder logic programming.
2.1
Memory Areas
The internal device memory in the PLC is broken into many different areas based
on their function. Some of these addresses refer to single bits, while some refer
to 16-bit registers. This section is a review of the memory areas covered in the
PLC Basics class, and includes some additional memory areas.
2.1.1 Discrete I/O (X/Y)
9
9
9
9
X represents a physical input.
Y represents a physical output.
Each address refers to a single bit.
In the L Series, inputs and outputs are addressed in hexadecimal.
2.1.2 Memory Bits (M/L)
9
9
9
9
M represents a memory bit.
L represents a memory bit which is latched by the PLC battery.
Memory bits are addresses in decimal.
The number of each address type is adjustable.
2.1.3 Data Registers (D)
9 D represents a data register.
9 Data registers are addresses in decimal.
9 The number of data registers is adjustable.
Notes
LESSON 2 – Controller Basics
Page 18
In L Series, the PLC has the ability to directly access bits within a word.
By placing a decimal point between the word address and bit address, you
can reference the status of a single bit within a word. An example would
be D100.0 which references the least significant bit in word D100.
2.1.4 Timers and Counters (T/ST/C)
9
9
9
9
9
T addresses are used to represent a timer.
ST addresses are used to represent retentive timers.
C addresses are used for counters.
Timers and counters are addressed in decimal.
The number of each address type is adjustable
Timers and counters will be covered later in this lesson.
2.1.5 Fault Annunciators (F)
An F indicates a fault annunciator address, which can be used by the user
to create fault indications in the controller.
When an F bit is
turned on, the number
of that bit as well as
the number of active
annunciators is stored
into special memory
addresses. The
USER LED on the
front of the CPU is
also on when any F
bits are on.
Notes
LESSON 2 – Controller Basics
Page 19
2.1.6 Step Relays (S)
Step relays are used for programming in the sequential function chart
(SFC) programming language. SFC is similar to a flowchart, and each
block of the chart is assigned a number.
Each S address refers to a single bit. This bit is used to indicate which
step in the flowchart is currently active. As program execution transfers
from one step to the next, step bits will be set and reset.
If not using SFC programming, the S addresses can NOT be used as
internal bits. This will cause an SFC error and the PLC will be stopped.
2.1.7 File Registers (R)
File registers are additional numeric data storage locations in the PLC.
These registers operate in similar fashion to the D registers. They can be
used for 16-bit numbers or 32-bit numbers the same way standard data
registers are, in all of the same commands.
File registers are configured by default in the L Series, but are created in
data registers (D). The amount and allocation can be adjusted in PLC
Parameters if required. The number of file registers and their storage
location is adjustable.
Notes
LESSON 2 – Controller Basics
Page 20
2.1.8 Index Registers (Z)
Index registers are used for offset addressing. They are indicated by Z
addresses. A number is stored in a Z register, and that number is used as
an offset for an address used in a PLC program. There are 20 index
registers available in the L Series processors.
The index registers can
be used to modify most
addresses in the PLC, as
well as numeric constants
in decimal and
hexadecimal.
Index registers can
also be used for 32-bit
offsets, in which case
2 consecutive index
registers are used to
store the offset value.
2.2
Constants
To use numeric data in PLC commands, it must be prefixed with a letter to
indicate the type of numeric data. Numbers can be put in decimal, hexadecimal,
or real number format depending on the commands used and the prefix assigned
to the number.
9 K indicates a decimal numeric value (16 or 32-bit).
9 H indicates a hexadecimal numeric value (16 or 32-bit).
9 E indicates a floating point numeric value.
Text can also be entered in the ASCII format by enclosing it in double quotes.
9 “Mitsubishi’ is an ASCII text string.
Notes
LESSON 2 – Controller Basics
2.3
Page 21
System Addressing
This section will quickly review the rules of I/O allocation for the L Series. A more
thorough review is part of the PLC Basics class.
•
•
•
•
•
•
Notes
All I/O addressing can be done automatically or set in PLC Parameters.
The CPU will read the connected modules at power-up. Manual
configuration is not required.
L Series uses a free addressing system. Addresses are allocated based
on the density of modules.
Addresses are allocated in blocks of 16. All I/O addressing is in
hexadecimal. If an 8-point module is used, it uses addresses 0-7, and
addresses 8-F are lost. Each module’s starting address always ends in 0.
Intelligent modules are referred to by their head address, which is the first
I/O address assigned to the intelligent module. Intelligent modules can
have both X and Y addresses.
L Series CPUs have 16 inputs and 8 outputs built in. These will occupy
X0-XF and Y0-Y7 in the default configuration.
L26CPU-BT has a CC-Link module built in, which is a 32 point intelligent
module. It will use addresses 10-2F in the default configuration.
LESSON 2 – Controller Basics
2.4
Page 22
EXERCISE – Addressing
Determine the correct I/O addressing of the L Series controller on the trainer unit.
Notes
LESSON 2 – Controller Basics
2.5
Page 23
Ladder Review
This section will review the basics of ladder logic. This material is covered in
detail in the PLC Basics training class.
Ladder logic is composed of many symbols. The ladder logic language is
designed to mimic an electrical power flow diagram, promoting ease of use with
electricians.
The basic symbols of ladder logic are contacts and coils. Inputs are represented
as contacts. Contacts with arrows are pulsed, either on the rising or falling edge
of the input signal. Outputs are represented as a coil.
AND conditions in logic are created by drawing contacts in series. OR conditions
are created by drawing contacts in parallel.
Other instructions are all represented as function blocks. The number of
parameters a function block requires depends on the instruction.
Some basic ladder logic commands include:
•
•
•
•
•
•
SET – latches a bit on
RST – resets a latched bit (or a register)
BKRST – block reset a range of addresses
PLS – rising edge pulse
PLF – falling edge pulse
FF – alternates the state of a bit
In order for a rung of code to be considered valid, it must have a minimum of one
input condition and one output condition. Input conditions are contacts and
output conditions are coils or instructions.
Notes
LESSON 2 – Controller Basics
2.6
Page 24
Timers
There are two basic types of timers available in the Q Series or L Series
processors. These two types are low speed and high speed timers. The
difference between low speed and high speed timers is the time base intervals
which can be timed. The actual preset time base for each type is adjustable in
PLC parameters, and applies to all timers of that type in the entire project.
•
•
Low speed timers have presets in increments of 1 to 1000ms
High speed timers have presets in increments of 0.1ms to 100ms.
To adjust the time bases, a setting must be made
in the PLC Parameters. On the PLC system tab,
the time base settings are in the top left as shown
below.
Either type of timer is available in a non-retentive or
a retentive form. The non-retentive timers will reset when deactivated. Retentive
timers will retain their current value when deactivated, and will continue from that
value when reactivated.
Notes
LESSON 2 – Controller Basics
Page 25
Retentive timers are not allocated by default. In order to
use retentive timer addresses, memory must be reserved
for their storage on the Device tab in PLC parameters.
To do this, enter a number in the ‘Device Point’ column
next to Retentive timer (ST). This number must be a
multiple of 16, or input in K (1024 addresses per K). It
may be necessary to reduce another address range to
make room for these new timer addresses.
When coding a timer in a ladder program, the output coil
symbol is used. A timer address is referenced for the
location to store this timer’s current value. A preset is
also given to tell the timer how long it is to run. This
preset can be a fixed numeric value or the value of a value in a data register.
To enter a low speed timer, draw an output coil, and enter the timer number,
followed by a space, and then the preset value.
Notes
LESSON 2 – Controller Basics
Page 26
To enter a high speed timer, draw an output coil, enter an ‘H’ followed by a space,
then the timer address, and then a space, and then the preset value.
To check for the completion of the timer in the logic, a contact is coded on the
same address as the timer. The H for high speed is not required on the contact.
Timers have some basic limitations in their operation:
•
•
•
Timers time up from zero to their preset, so negative presets are not
allowed.
All timers are 16-bit, so largest preset value is 32,767.
Timers do NOT count past their preset value.
The method to reset a timer depends on whether or not it is a retentive timer.
•
•
•
Notes
Non-retentive timers are reset when the logic in front of the timer coil turns
false. They can also be reset with the RST instruction.
Retentive timers require the use of the RST instruction.
If not marked as latched in the PLC parameters, the timer value will be lost
when controller power is cycled.
LESSON 2 – Controller Basics
2.7
Page 27
Timer Examples
Since all timers time up to their preset values, it is necessary to write code to
create various types of timers. Some examples are below.
On Delay Timer
•
Output Y11 will turn on 10 seconds after input X1.
Off Delay Timer
•
Output Y12 will turn on with X2 and remain on for 10 seconds after X2
turns off.
Flip Flop Timer
•
Notes
Output Y14 will be on for 5 seconds and off for 10 seconds, repeating as
long as the CPU is in RUN mode.
LESSON 2 – Controller Basics
Page 28
One Shot Timer
•
Output Y16 will turn on with X6 and turn off after 10 second, even if X6
stays on longer than 10 seconds. If X6 turns off in less than 10 seconds,
the output on Y16 will be the same length as the input.
One Shot Fixed Length Timer
•
Same as above, but the M7 output will always be 10 seconds long, no
matter how short of a time the X7 input signal remains on.
Cascaded Timers
Since the maximum preset is 32,767 and a typical low speed timer is set in 10th
of a second, timers cannot exceed 3276.7 seconds. To time for 5000 seconds,
two timers can be cascaded as shown below.
•
Notes
Y18 turns on after X8 has been on for 5000 seconds (preset would be
50,000 (out of range) with a single timer).
LESSON 2 – Controller Basics
2.8
Page 29
Counters
All L Series and Q Series CPUs have 1024 counters configured by default. As
with the timers, the allocation of memory can be modified to allocate more or less
counter addresses.
Counters operate by incrementing a value each time the logic in front of the
counter coil is turned on. This function only counts once, on the rising edge of
the input condition, so the input condition does not need to be pulsed.
Counters are coded as an output coil, just as timers. A preset must be defined
when the counter is created. The preset is a 16-bit number, and can be a fixed
numeric value or a reference to a value in a data register.
To check for the completion of a counter in ladder logic, code a contact with the
counter address.
Counters have some basic limitations in their operation:
•
•
•
Counters count up from zero to their preset, so negative presets are not
allowed.
All counters are 16-bit, so largest preset is 32,767.
Counters do NOT count past their preset value.
Counters are reset using the RST instruction. If not marked as latched in the
PLC parameters, the count value will be lost when controller power is cycled.
Notes
LESSON 2 – Controller Basics
Page 30
Since counters only count up, some users will attempt to cause a counter to
count down using the DEC (decrement) instruction. This is not advised, since
the counter completion signal will not be modified by instructions other than the
counter coil. If the counter is completed and a DEC is performed, the counter will
lower its count by one, but the completion indicator will NOT turn off. By the
same token, if the INC (increment) instruction is used, the counter may go past
its preset value, and the completion indicator will not be updated.
2.9
Counter Examples
Notes
•
•
•
Each time X0 turns on, counter C0 increases by one.
When C0 reaches its preset, output T10 turns on.
Y10 will remain on, and the counter will not count again, until the counter
is reset by X1 turning on.
•
•
When X1 is on, count seconds (using SM412, 1-second clock pulse).
Output Y11 will turn on for one scan when the counter completes, and the
counter will be reset and continue to run.
LESSON 3 – GX Works2 Introduction
Page 31
LESSON 3 – GX Works2 Introduction
This lesson is intended to introduce the GX Works2 software and allow the user to
understand the options for customizing the user interface.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Understand the new features of GX Works2.
• Customize screen layout, keyboard settings, and software preferences.
3.1
GX Works2 New and Improved Features
Many improvements were made to the GX Works2 programming software,
making it easier to use and more user friendly. Some of them are listed below.
Improved Ease of Use
•
•
•
•
•
•
GX Works2 operating manuals are installed during the installation process
and readily available from the Help menu.
Help menu now offers helps on all instructions, similar to the contents of
the programming manual, available by pressing F1 on an instruction.
Function block libraries, with drag and drop usage from selection window.
Some function blocks can be resized in the structured ladder programming
mode, allowing more inputs to certain instructions.
Text of label names and function names supports auto-complete while
typing in the editor windows.
Compress and unpack utilities in the Project menu to package a project for
transmission on disk or email.
Improved User Interface
•
•
•
•
Notes
More use of docking windows in GX Works2, allowing commonly used
components to be docked anywhere in the workspace.
Toolbars automatically change based on the type of open window.
Many keyboard shortcuts are able to be modified by the end user.
Screen colors can be customized for user preferences
LESSON 3 – GX Works2 Introduction
Page 32
New Features
•
•
•
•
3.2
Built-in comments for special relays and registers can be imported into
project from right click in comment list.
Built-in comments for special function modules, also available for insertion
by right click menu in comment list.
Complete project revision history function, allowing multiple versions of the
program to be registered into the same project, verified against each other,
or restored.
Multi-level project security, allowing the programmer to choose which
security levels have access to which portions of a project.
Backward Compatibility
The GX Works2 software is capable of reading projects which were written in GX
Developer for any PLC type available in GX Works2. These projects can be
opened using the ‘Open Other Data’ option in the Project menu.
To open a GX Developer file,
navigate to the directory which
contained the ‘gppw.gpj’ file in the
GX Developer project directory. This
dialog will confirm reading of the GX
Developer data type.
GX Works2 can save simple projects back into a GX Developer compatible file
format. This allows programs which were modified in GX Works2 to be opened
in older versions of GX Developer.
In the Project menu, select ‘Export to
GX Developer Format File…’ to start
the utility and indicate where to save
the project. Saving of structured
projects in the GX Developer format is
not allowed.
Once ‘Yes’ is selected, a project will be created in the GX Developer format for
use in the GX Developer software.
Notes
LESSON 3 – GX Works2 Introduction
3.3
Page 33
File Format
All iQ Works titles use a new file storage format, which is consistent throughout
the packages. Projects are now saved into a workspace. Each workspace can
contain projects from GX Works2, GT Works3, and MT Works2.
In the directory where the workspace is created, there will be a file called
‘workspacelist.xml’ which contains a list of the workspaces found in this directory.
Each workspace is stored in a directory with the same name as the workspace.
If MELSOFT Navigator was used to create a workspace, there will also be a file
with the same name as the workspace with the extension ‘.nvw’ which stores the
Navigator configuration.
In each workspace directory, there will be a file called ‘projectlist.xml’ which
contains a list of the projects found in this workspace.
Each project in the workspace will have its own subdirectory in the workspace
folder. All files relayed to that project are stored in the subdirectory. Double
clicking on the ‘Project.gd2’ file within that directory will open the project in GX
Works2.
When moving files from one drive to another, it is imperative that the
‘workspacelist.xml’ file and the directory named for the workspace is included
with all of its subdirectories. Without the ‘workspacelist.xml’ file, the projects
cannot be opened.
Notes
LESSON 3 – GX Works2 Introduction
3.4
Compress/Unpack
Using the Compress option on the
Project menu will compact all required
files into a single file, making it easier
to move or send via email. The
compressed file can be set to inherit
all registered revisions, and can be
divided into smaller pieces
automatically.
The Unpack utility allows the
compressed file to be expanded back
into a project in an existing workspace.
It can be extracted with a different
project name than it was created with,
in case a project of the same name
already exists on the destination
computer.
Notes
Page 34
LESSON 3 – GX Works2 Introduction
3.5
Page 35
Launching GX Works2
GX Works2 is Windows based programming software. Because it is a Windows
package, it can be started from the Start menu.
Start -> All Programs -> MELSOFT Application -> GX Works2
The GX Works2 installation process creates an icon on the desktop when it
completes, which can be used to start GX Works2.
GX Works2 can also be started automatically from within MELSOFT Navigator by
double clicking on a PLC with a project attached.
An example of the main GX Works2 screen is shown below.
The GX Works2 screen is broken into many components. Many of these
components, such as toolbars and certain windows, can be docked at various
locations around the screen, or their display can be turned off.
Notes
LESSON 3 – GX Works2 Introduction
Page 36
The work window on GX Works2 is broken into a series of tabs to indicate open
windows. It can also be tiled, cascaded, or arranged as windows.
Font size in the ladder window can be increased or decreased with the Text Size
option in the View menu. It is also available from the right click menu in the
ladder window. Display fonts and colors can also be adjusted in the View menu.
3.6
Docking Windows
There are a variety of windows which can be docked
to the edges of the screen in GX Works2. These
windows can be turned on and off using the Docking
Window option in the View Menu.
The docking windows which are enabled will have an
orange box behind the icon to the left of the window
name in the menu.
Any of the docking windows can be turned
on or off in the View menu or with the X
button in the upper right corner. Docking
windows will have a pin in the upper right
corner, and when clicked, it will turn the
window into a tab which slides in from the side of the screen.
Docking windows can be moved to any side of the screen.
Notes
LESSON 3 – GX Works2 Introduction
Page 37
Docking windows can be moved to various locations on the screen. To move a
docking window, click and hold the left mouse button on its title bar, and move
the mouse. Arrows will appear as shown below.
If the mouse is not over an arrow, the window becomes a floating window. When
the mouse moves over an arrow, it will dock to that side of the workspace.
Notes
LESSON 3 – GX Works2 Introduction
Page 38
When the mouse is over one of the arrows in the center, the docking window will
be placed on that edge of the current window, as shown by the darkened section
on the screen.
If there is a center button in the center arrow block, this will make the window
being moved into another tab in that window.
When the mouse is positioned over one of the arrows on the outside edge of the
screen, that docking window will be located completely across that side of the
screen, as shown below.
Notes
LESSON 3 – GX Works2 Introduction
3.7
Page 39
Toolbars
Toolbars in GX Works2 can be customized with the small arrow at the end of
each toolbar. Check or un-check a tool to update the toolbar contents.
Complete toolbars can be turned on or off from the View menu. Toolbars can be
repositioned or docked by dragging them around the screen.
The toolbars being displayed will change automatically as different windows are
open, such as the ladder toolbar in the ladder windows, or the device memory
toolbar in a device memory window.
A complete list of all toolbars, buttons, and shortcut keys can be found in
Appendix 1 of the GX Works2 Operating Manual (Common).
Notes
LESSON 3 – GX Works2 Introduction
3.8
Page 40
Customizing the Keyboard
Keyboard shortcuts used within GX Works2 can be customized using the Key
Customize option in the Tool menu.
On the left side of the window, select the command from the selection list. The
current keyboard shortcut (if any) will be displayed in the top right window. To
set a new key, click in the window under ‘Press a key to assign’ and enter the
new keystroke.
Changes can be saved as a template, and the default template can be restored
from this window as well. Templates can be imported and exported for use on
other computers.
Notes
LESSON 3 – GX Works2 Introduction
3.9
Page 41
Status Bar
The status bar on the bottom of the GX Works2 window shows the status of
various settings within the project for quick reference. The status bar is broken
up as indicated below.
•
•
•
•
•
•
•
Notes
The project type will be one of 3 settings
o ‘Unlabeled’ for a simple project without labels
o ‘Simple’ for a simple project with labels
o ‘Structured’ for a structured project
Security information will display the name of the currently logged in user
then a project with security settings active is opened
Programmable controller type will display the model number of the CPU
which this project is configured for
Connection destination will display the route being used in Connection
Settings to connect to the CPU
Cursor position will display the cursor position in the open window
The next box will display ‘Insert’ or ‘Overwrite’ depending on the edit mode
in the software, which can be changed by the INS key on the keyboard
The last two boxes show the status of the CAPS LOCK and NUM LOCK
keys on the keyboard
LESSON 3 – GX Works2 Introduction
Page 42
3.10 Software Options
The basic software options in GX Works2 are found in the Tool menu under
Options. On the left side of this window is a tree structure, which divides the
option settings into groups based on their function.
At the bottom of this window is a button to set the current options as a user
default. Another button will allow the restoration of that user default if changes
have been made. There is also a button to return to the factory defaults.
Several of the option settings will be discussed in more detail in other sections of
this training manual.
Notes
LESSON 4 – Creating a Project
Page 43
LESSON 4 – Creating a Project
This lesson will explain creating a project, editing basic ladder, and writing to the CPU in
GX Works2.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Create a new project in GX Works2.
• Enter ladder logic into the project.
• Configure communication settings for connection to the PLC.
• Read and write projects to/from the CPU.
4.1
Simple vs. Structured Project
There are two program types which can be created in GX Works2. These are
called simple or structured projects.
Simple projects allow the use of the standard Mitsubishi programmable controller
instruction set. Simple projects offer the same functions which were available in
GX Developer.
Simple projects can be written in:
•
•
•
Ladder
Sequential Function Chart (SFC)
Structured Text (ST)
Structured projects offer more functionality by offering IEC 61131-3 compliant
programming in multiple languages. In addition to standard Mitsubishi instruction
set, the IEC standard libraries are available in a structured project. This is similar
to the older GX IEC Developer software.
Notes
LESSON 4 – Creating a Project
Page 44
Structured programs can be written in:
•
•
•
•
Ladder
Structured Ladder
Sequential Function Chart (SFC)
Structured Text (ST)
More detail on the various programming languages will be provided in later
lessons in this class.
4.2
Creating a New Project
There are 3 ways to accomplish most tasks in GX Works2.
•
•
•
Shortcut key on keyboard
Button on toolbar
Pull down menu item
The first button on the Standard toolbar
is a white sheet of paper. The shortcut
key is Ctrl-N. New Project can be
selected from the Project menu. This
will present the New Project dialog box.
On this dialog box, the project type is
selected.
If label based programming is desired,
please check the Use Label box. Label
programming allows names to be assigned to PLC addresses to facilitate coding.
Select the PLC series and PLC type for your controller. PLC Series should be L
Series. Select the PLC Type based on the provided training hardware.
Label programming and structured programs are covered later in this class. For
now, select ‘Simple Project’, and do not select to use labels.
Notes
LESSON 4 – Creating a Project
4.3
Page 45
Editing Ladder Logic
Ladder logic can be entered in 3 ways.
•
•
•
Buttons on the toolbars can be pressed to draw a symbol where the cursor
is positioned.
Double clicking inside the cursor box will allow the symbol to be selected
from a drop down list.
A keyboard shortcut exists for each ladder logic symbol.
After creating or modifying ladder logic, the code is highlighted in gray. The gray
portion of the code has not been compiled. Compiling is the process GX Works2
uses to review the logic changes and verify that the structure of the ladder logic
is valid. The logic can be compiled with the F4 shortcut key, or by selecting Build
from the ‘Compile’ menu.
If there are errors, such as no input condition or unconnected lines, the compile
will fail with an error message. The software will not allow a project to be
downloaded or saved until the code is compiled without errors.
Notes
LESSON 4 – Creating a Project
4.4
EXERCISE – Basic Ladder Logic
Enter the program shown here. Do not download to the PLC yet.
Notes
Page 46
LESSON 4 – Creating a Project
4.5
Page 47
Connection Setup
The first step in transferring the program to the PLC is the configuration of the
connection options. In the navigation window is a button called Connection
Destination. There is a configuration called Connection1 here by default.
Multiple configurations can be defined here. When one is double clicked, a
screen similar to the one below is shown.
Notes
LESSON 4 – Creating a Project
Page 48
The first row of options on the top of the screen is the PC side interface. This is
where the connection on the PC end is configured. The options available
depend upon the PLC type selected.
The second row of options is the PLC side interface. This row is used to
configure the connection at the PLC end. GOT Transparent Mode now has its
own setting in this row.
The yellow boxes indicate the currently selected method. Double clicking on
many of these buttons will bring up more detailed configuration data.
The ‘Connection test’ button will allow the configuration to be tested to the
connected PLC. If all settings are correct, a dialog box indicating successful
connection will be displayed.
The ‘Connection Channel List’ button will allow the selection of configuration by
picture. It shows all available connection methods. When one is selected and
the Update button is pressed, the settings to accomplish this will be made in the
Transfer Setup screen.
Pressing the X button in the upper right hand corner or clicking the ‘Close’ button
will result in settings not being saved. To save the changes, the Transfer Setup
screen must be closed by pressing the ‘OK’ button.
Set the appropriate settings for the connection method being used on the trainer
unit.
With GX Works2, multiple connection configurations can be defined. By right
clicking on a connection in the Connection Destination list, that connection can
be copied, renamed, deleted, or set as the default connection. This allows
multiple communication paths to be configured in a single project and easily
switched.
Notes
LESSON 4 – Creating a Project
4.6
Page 49
Transferring to the PLC
Once the connection has been configured, the program can be written to the PLC
using the ‘Write to PLC’ option in the ‘Online’ menu.
Across the top of the window are radio buttons to select read from PLC, write to
PLC, verify with PLC, and delete PLC data.
There is a tab labeled Intelligent Function Module, which is used to download
data directly to an intelligent module, such as writing to Flash ROM in QD75MH
modules. It is not required for L Series intelligent module data.
The components of the program will be shown in the middle window. Each
component can be checked to include it in the download. Checking only the
components which need to be sent can improve communication speed. There
are quick select buttons for parameters and programs only, select all objects, or
unselect all objects above the window.
Notes
LESSON 4 – Creating a Project
Page 50
Some items in the transfer list will show a ‘Detail’ button next to them. The detail
settings can make changes to the download information.
•
•
•
For the PLC programs, the detail button allows modification of the number
of write during run steps of memory which are reserved automatically in
each program
For the comments, the detail button allows the setting of ranges of
comments which will be sent to the processor.
For device memory, the detail button determines the ranges of the device
data to be written to the CPU.
Across the bottom of the transfer window are quick buttons for other online PLC
functions. These functions include:
¾
¾
¾
¾
¾
¾
¾
Start/Stop the PLC
Set the PLC Clock
PLC User Data (read and write memory card data)
Write Title
Format PLC memory (erase program memory)
Clear PLC memory (erase data registers and/or file registers)
Arrange PLC memory (defragment and arrange program memory)
These functions can be hidden by clicking on the ‘Related Functions’ button at
the bottom of the transfer window.
Select to download the parameters and programs. Ensure that the target
memory is ‘Program Memory’ and click ‘Execute’ to write the selected objects to
the PLC.
If the controller is running when the download
starts, a warning will be presented asking if you
wish to stop the processor. It is necessary to
stop the PLC in order to perform a download.
This will stop the controller and return the outputs
to the off state. Be sure the controller is not
performing a critical task or running operating
equipment before clicking ‘Yes’.
Notes
LESSON 4 – Creating a Project
The software will also issue warnings if
parameter or program data in the
controller will be overwritten during the
download process. Click ‘Yes’ to
overwrite the existing information and be
prompted for each additional duplicate
item, or click ‘Yes to all’ to overwrite all
data without further prompts. To keep data in the controller, click ‘No’.
When the download completes, a screen will
be displayed which shows the processes
completed, in the order in which they were
completed.
This screen can be suppressed in the future by
checking the box at the bottom labeled ‘When
processing ends, the window is automatically
closed.’ Otherwise, click the ‘Close’ button at
the bottom of the window to complete the
download.
Once the download completed screen is
closed, there may be a prompt to switch the
PLC back into the RUN mode.
If the controller was in the RUN mode when
the download was started, GX Works2 will
ask if it should restart the processor. If the
controller was in the STOP mode, it will not
ask this question. Click ‘Yes’ to restart the
processor.
Notes
Page 51
LESSON 4 – Creating a Project
4.7
Page 52
Reading from the PLC
To read the program already in the PLC, use the ‘Read from PLC’ option in the
‘Online’ menu. Any programs, parameters, comments, or data from the PLC
memory can be uploaded from this screen.
Only the objects which actually exist in the PLC will be shown, so if comments
were not downloaded to the PLC, the Comments box will not appear in the ‘Read
from PLC’ dialog box.
The ‘Device Data’ option will upload the values stored in the PLC’s data registers.
Notes
LESSON 4 – Creating a Project
4.8
Page 53
Verify with PLC
To compare the PLC program or parameters in the PLC with the one in the open
GX Works2 project, use the ‘Verify with PLC’ option in the ‘Online’ menu.
Check the items to verify in both columns, and then click ‘Execute’. A separate
window will appear with the results of each verify selected.
Notes
LESSON 4 – Creating a Project
Page 54
There is a second verify option, used to compare 2 GX Works2 projects instead
of one project and one PLC. This option is found in the ‘Project’ menu. The
‘Verify’ option will compare the open project with another one specified on the
verify screen.
Notes
LESSON 5 – Online Operations
Page 55
LESSON 5 – Online Operations
This lesson will cover the online monitoring and modification tools in GX Works2.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Monitor the operation of the program in the CPU.
• Perform online edits to a running PLC program.
• Force bits and change register values.
There are numerous tools in GX Works2 for monitoring the status of a PLC. Some of
these options are:
•
•
•
Online monitoring of ladder logic
Device / Buffer Memory batch monitor
Watch windows
The monitoring tools are found in the ‘Online’ menu under the ‘Monitor’ submenu.
5.1
Ladder Logic Monitor
The status of ladder logic can be displayed while online with the PLC. This will
highlight the inputs and outputs which are on, and display numeric data for data
registers.
To start the ladder logic monitor, select the ‘Online’ menu; select ‘Monitor’ and
then select either ‘Start Monitoring’ or ‘Start Monitoring (All Windows)’. The
shortcut key to start monitor in a single window is F3. Monitoring can be stopped
for a window with Alt-F3.
There are also buttons on the toolbars to start and stop monitoring. They are
found next to the buttons for write to PLC and read from PLC on the Program
Common toolbar.
Notes
LESSON 5 – Online Operations
Page 56
When monitoring is active, the monitor toolbar will be shown. This toolbar shows
the connection status, PLC mode, PLC and USER error status, maximum scan
time since connected, and local device monitor status for L Series controllers.
The contacts or coils which are on will be highlighted. Notice the connection
lines are NOT highlighted. Any command which uses numeric values will
indicate the values directly below their elements in the ladder diagram.
Notes
LESSON 5 – Online Operations
5.2
Page 57
Device / Buffer Memory Batch Monitor
The device and buffer memory batch monitor is used to view a number of
sequential addresses of PLC data or consecutive buffer memory locations in an
intelligent module.
On the top of this window, one address and one display format can be configured,
and when the ‘Start Monitor’ button in the toolbar or Enter is pressed, the screen
is populated from that address forward. Individual display formats or nonsequential addresses cannot be monitored with this utility.
The lower half of the window will change based on the type of data from the
address specified at the top and the display format specified.
Notes
LESSON 5 – Online Operations
Page 58
Up to 64 device batch monitor screens can be created. Each will be assigned a
number. If still open when the program is saved, the screens will be saved as
part of the project, and will be available when the project is opened again.
The ‘Display Format’ button allows the configuration of the type of
data and method of display to be shown. This will bring up the
dialog box shown below. Any settings made on this window will apply to all
addresses shown in the device batch monitor.
Display formats can be saved and loaded
from the Device / Buffer Memory Batch
Monitor window. This allows a
configuration to be designed and reused
in other projects.
Notes
LESSON 5 – Online Operations
5.3
Page 59
Watch Windows
In GX Works2, there are 4 data watch windows which can be turned on or off and
docked on the screen. Watch windows can be turned on or off from the ‘View’
menu under ‘Docking Window’. Just as the project tree, these windows can be
pinned open or minimized to tabs.
Each of the specific devices to watch in a window is configured by the user. Data
can be added to a watch window from within the watch window by typing a value
into the first column of the table. Each item in the table can have its own data
type configured, so monitoring of 16-bit, 32-bit, and floating point data on the
same window is possible.
Another method for entering data into the watch window is to right click on and
address on the ladder diagram and select ‘Register Watch’. Entire structured
ladder blocks can be registered by performing this step on the gray box at the left
of the block. All addresses used in that ladder block will be added to the watch
window. Multiple ladder blocks can also be selected. Items entered from this
option go to the lowest number watch window which is open, whether pinned
open or not.
Monitoring on each window can be started and stopped separately, and without
the ladder monitor window being in monitor mode.
Monitoring in the watch windows can be started with Shift-F3 or from the Start
Watch command in the Online menu under Monitor. Shift-Alt-F3 will stop
monitoring in a watch window.
Closing these windows will not delete the addresses which were registered.
Notes
LESSON 5 – Online Operations
5.4
Page 60
Intelligent Module Monitor
GX Works2 offers a docking window for monitoring of intelligent module data. Up
to 10 of these windows can be used to monitor different intelligent modules.
To turn this window in, select the ‘View’ menu, then ‘Docking Window’, then
‘Intelligent Function Module Monitor’, and then select a monitor window number 1
through 10.
Modules can be registered into the monitor windows in one of 3 ways.
•
•
•
Right click on the intelligent module in the project tree, then select
‘Register to Intelligent Function Module Monitor’
Drag and drop a module from the project tree into the intelligent module
monitor window
Right click on the intelligent module monitor window and select ‘Register
Module Information’
The monitor window below is for a L60AD4 analog module. Some values (shown
in white) can be changed in the Current Value column.
Notes
LESSON 5 – Online Operations
5.5
Page 61
Online Edits
Program changes can be made online with the L Series controller while it is
running. It is not necessary to stop the controller for basic program changes.
Each L Series program has a buffer of program steps for modification of a
program while it is running. The default is 500 steps of program memory are
reserved for each program, but this number is adjustable for each program
individually. If this buffer fills, the only way to empty it is to stop the CPU and
perform a complete download of the project.
Editing ladder online must be done while in the monitor mode. If F4 is pressed to
convert ladder changes, the change is only made offline in the GX Works2
project. The PLC program is not updated at this time.
To make the edits to the PLC program while the PLC runs, a different command
is used to convert the code. This command is found in the Compile menu, and is
called Online Program Change. It is also accessible via the Shift-F4 shortcut key.
It is imperative that the PLC program and the open project match before an
online edit is made. If the programs do not match, the edits will not be applied
and this error message will be displayed.
Notes
LESSON 5 – Online Operations
Page 62
When converting online changes, a dialog box appears indicating that the
program currently executing in the CPU will be modified while it is running.
By clicking ‘Yes’, the program in the CPU will be updated without stopping
the controller. At the end of the next scan, program changes will be
applied.
When the online edit completes, a dialog box will indicate success, and
will display the number of write during run steps left in the buffer.
Notes
LESSON 5 – Online Operations
5.6
Page 63
Modify Value
The modify value function is used to modify the value of a bit or word address in
the PLC. It should not be mistaken for a method of forcing inputs or outputs.
Modify value can be used by:
¾ Right click on an object and select Debug, Modify Value
¾ Debug menu, Modify Value
¾ Holding the shift key and double clicking on a contact or coil
¾ Shift-Enter on a contact or coil
Modify value can be used to turn a bit on or off.
It is considered a momentary override of an
address. There is no warning or visible
indication that an address was modified. A
history at the bottom of the window shows
previously used addresses, and can be hidden
if desired.
The PLC inputs take priority, so modifying an
input will result in a momentary signal. At the
beginning of the next scan, the PLC’s inputs are
read, and overwrite any modified input
addresses. The programmed output status also
takes priority, so a modified output will revert to
its programmed status after one scan. When
the program scan finishes, all outputs are updated, which also overwrites any
modified output addresses used in the program.
Modify value can also write a number to a data
register, or write a number to a buffer memory
address in an intelligent module. It can also be
accessed from the Device / Buffer Memory
batch monitor screen.
Notes
LESSON 5 – Online Operations
5.7
Page 64
Forced I/O Registration
Forced I/O Registration is used only for X and Y addresses, and eliminates the
limitations mentioned for device test. In this mode, an address can be set forced
on or forced off, and it overrides the physical inputs and programmed outputs.
Forced I/O Registration/Cancellation can be found in the Debug menu, or in the
Debug menu on the right click menu.
Forced I/O registration only works
in the L Series and Q Series CPUs
(excluding basic model).
Only X and Y addresses can be
registered. Once registered, that
address is not affected by the
inputs or programmed outputs in
the programs.
To add an address to the list, enter
the address in the Device window,
and click ‘Set forced ON’ or ‘Set
forced OFF’ depending on the
desired mode.
To remove an address which is
forced, enter the address in the
Device window and click ‘Cancel it’.
All forces can be cancelled at once with the ‘Clear all’ button at the bottom of the
screen.
The ‘Update Status’ button will read the forced I/O table from the connected CPU.
While forced I/O registration is active, the MODE light on the front of the
processor will be flashing. When the registration is cancelled, the LED will return
to the solid on state. There is also an icon in the Online toolbar in GX Works2 to
indicate the forced I/O registration activity.
Notes
LESSON 5 – Online Operations
Page 65
When exiting this window, a
message will prompt asking to
clear all forced I/O status. If
‘Yes’ is selected, all forces will
be erased, the same as clicking
‘Clear all’ in the window.
If ‘No’ is selected, the forces remain in effect.
When connecting GX
Works2 or GX Developer
to a CPU which has active
forces, a message is
displayed indicating that
there are active forces in
the CPU. To see what
addresses are forced or
modify the forces, open the force I/O registration window.
Forced I/O Registration is cancelled when a CPU is powered off, or by resetting
the PLC.
Notes
LESSON 6 – GX Works2 Utilities
Notes
Page 66
LESSON 6 – GX Works2 Utilities
Page 67
LESSON 6 – GX Works2 Utilities
This lesson introduces some of the editing and troubleshooting features of the GX
Works2 software.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Use the options in the find/replace menu.
• Run and interpret the PLC Diagnostics screens.
• Utilize the System Monitor tool to troubleshoot hardware.
• Execute a sampling data trace.
6.1
Find/Replace Menu
GX Works2 provides several different
methods for locating devices or
instructions. The Find/Replace menu has
a variety of tools for searching or
modifying programs. The find options will
search a program for an occurrence of an
address or instruction. The replace
options will allow the replacing of
addresses, functions, open/closed
contacts, and other options. The Cross
Reference will show all occurrences of an
address in a program, and the Device List
shows all used addresses in the program.
Shown to the right is the list of options on
the Find/Replace menu.
Notes
LESSON 6 – GX Works2 Utilities
Page 68
Find Device is used to find a device address regardless of the instruction. It will
search the entire program for a particular address. There are a couple of options
on this screen. At the top, you can limit the search area.
This same dialog can be used to replace devices.
The option setting includes other possible matches in the results.
Digit allows the find to look for a bit address in a word of bits. A digit
search of the following code will find that M110 has been used as part of
this TO instruction.
Double Word expands the search to include a word that is used by an
instruction using multiple words. A double word search of the following
code will find that D5 has been used as part of this FROM instruction,
since it writes to 6 addresses starting at D0.
Notes
LESSON 6 – GX Works2 Utilities
Page 69
Replace Device allows search and replace of a device or a range of devices
within the program. A single address can be specified for the earlier device and
for the new device. The number of substitute points sets how many consecutive
addresses to move. The radio buttons for move comments allows comments
assigned to an address to be moved with the address. The find direction options
allow the search and replace to be restricted to a certain portion of the program.
Replace of addresses is not done as an online edit. The program must be
downloaded after a replace is complete.
The Find Next button will find the next location of the searched data. There is no
find previous button, but by switching the direction to up and picking Find Next,
the same function can be achieved.
The All Find or All Replace buttons will find or replace all locations of the desired
text.
The second tab from the right is called Result. In this window, all of the found or
replaced data can be viewed. Items in the results window can be double clicked
for easy program navigation.
The last tab is called Error Log, and it is used with the replace window to indicate
any errors which occurred in the replace process.
Notes
LESSON 6 – GX Works2 Utilities
Page 70
Find/Replace can also be used as a docking window. To turn on this window,
open the View menu, select Docking Window, and then select Find/Replace
Window.
Find Instruction is used to locate all instances of a particular instruction. The
first selection box selects the ladder symbol and the second selection box selects
the command to search for. The find direction section works as previously
discussed.
This same dialog can be used to replace instructions.
Replace Instruction will change one instruction type to another. The earlier
instruction is the type of instruction to replace, and the new instruction is the
instruction to substitute into the program. This can be useful for example to
replace all occurrences of INC with INCP in a program.
¾ Replace of instructions is not done as an online edit. A download of the
program must be done after a replace is complete.
Notes
LESSON 6 – GX Works2 Utilities
Page 71
Find Contact or Coil uses the same dialog and will search the program for an
address used as either a contact or a coil. In the first window, select contact or
coil. Then in the right window, enter an address. This can be handy when an
address has been used as a contact numerous times in a program to find the one
location it was used as a coil.
The Find String option searches a target for a text string. This string can be in
addresses, comments, statements, notes or labels.
A setting at the top of the window allows the search range to be limited.
Notes
LESSON 6 – GX Works2 Utilities
Page 72
The same dialog is used with replace, simply by entering data in the Replace
String field. It can also be opened from the Replace String option in the
Find/Replace menu.
Settings on the bottom of the window allow adjustment of the direction of search,
whether the search is case sensitive, and whether to only match whole words.
Change Open/Close Contact will change all occurrences of an open contact to
a closed contact and change closed contacts to open. A single command will
invert the state of all occurrences of the address. This is useful if the type of
input provided to a machine changes or does not match the code, such as a
program which is expecting a normally closed stop signal and the machine is
wired with a normally open switch.
Notes
LESSON 6 – GX Works2 Utilities
Page 73
Device Batch Replace takes the Replace Device option a step farther. It allows
the programmer to replace multiple ranges of devices in a single command.
Groups of timers, counters, inputs, and data registers can all be acted on at once.
Each line in the chart is a different range of addresses. Addresses cannot
overlap in any rows.
Notes
LESSON 6 – GX Works2 Utilities
Page 74
Change Module I/O Number allows the programmer to change the head
address of a special function module. This code will search a program and
change all occurrences of the head address, such as TO or FROM instructions.
By specifying a start and end as different values, a range of intelligent modules
can be moved at once. Enter the start and end SFM numbers, and enter a single
new module number. The software will move the old addresses to a range of
equal size starting at the new module address.
This tool does not change U\G addresses. It is only supported in the basic
ladder language.
Notes
LESSON 6 – GX Works2 Utilities
Page 75
Switch Statement/Note Type is
used to change embedded status of
statements and notes. Q Series
and L Series offer the option to
embed statements and notes into
the program when it is downloaded
to the CPU. ‘Change in Peripheral’
means the statements or notes only
exist in GX Works2. ‘Change in
PLC’ means they are part of the
PLC code and are sent to the PLC
with the download of the program
code.
The replace can be limited to a certain section of a program or the entire program,
only statements, only notes, or both statements and notes.
If the CPU is low on memory, this tool can be used to remove the documentation
from the CPU memory. All documentation can still be viewed with a copy of the
GX Works2 project, but will not be in the CPU to be uploaded.
Jump will jump to a step number in the program.
This can be useful with the error information
previously discussed to search out the location of
a program error in the program.
Notes
LESSON 6 – GX Works2 Utilities
6.2
Page 76
Cross Reference
A cross reference is a list showing all of the times an address was used in the
program and in what type of instruction. Cross reference can search the open
program, or all programs in the open project. Cross reference information is
displayed in a docking window. Cross reference can be used on a single
address or all addresses at once.
To configure options, use the Options tab. Settings here include an option
similar to the digit/multiple word (as discussed with Find Device). The ‘Set
device other than head as find target’ option replaces the digit and multiple word
option with a single check box.
To perform a cross reference and see the results, enter the address and click the
Find on the Cross Reference Information tab.
Double clicking on an item in the cross reference window will jump the program
display to that location.
Cross reference can also be accessed from right-clicking on any address in the
ladder diagram.
Notes
LESSON 6 – GX Works2 Utilities
6.3
Page 77
Device List
The Device List will show a list of all of the devices used in the program. The list
can be configured to show a single program or all programs in the CPU.
The locations to search can be defined in the ‘Find in’ box. This location can be
a program, the program pool, PLC parameters, intelligent function utility, or the
entire project.
An address is entered in the device box, and after pressing the Find button, the
list starting at that address is shown in the window below.
There are columns which will show an asterisk (*) if that address has been used
as an input, output, or in parameter settings. Inputs include source data for
applied instructions and outputs include destinations of applied instructions. If
comments are registered, they will show in the Comment column
The Device List is also a docking window.
Device List is also accessible from the right click menu in a ladder diagram or by
the Ctrl-D shortcut key. The window will be populated with addresses starting at
the address of the item clicked on, and automatically executed.
Notes
LESSON 6 – GX Works2 Utilities
6.4
Page 78
PLC Diagnostics
GX Works2 has built in diagnostics capability to assist the user with
troubleshooting a PLC error. The PLC Diagnostics screen provides an easy to
understand interface for data which is stored inside the CPU in the special relays
and registers.
Please create a new simple project and enter the rung shown below:
Take a moment to examine the above logic. What happens when X0 is turned
on? The first value (4) is divided by the second value (0) and the result is placed
into D0.
Dividing by zero is an illegal operation, since the result is an infinite number.
Trigger X0 and watch what happens. The error light on the CPU comes on. The
RUN light also goes out, which indicates the PLC is stopped.
To troubleshoot do the following steps:
•
•
Notes
Click on the Diagnostics pull down menu.
Click on PLC Diagnostics.
LESSON 6 – GX Works2 Utilities
Page 79
A screen like the one below appears:
At the top of this window are the current operating mode and the run/stop switch
setting on the CPU.
On the left is a picture of the CPU showing the active LEDs. Moving the mouse
over various sections of the processor shows different popups, showing memory
card options, remote operation, and diagnostic options.
In the center of the screen is the active alarms list. This shows the currently
active alarm number in the CPU.
Below this is the PLC’s alarm history. This is the alarm history for the PLC
selected in the top window. It can be exported to a CSV file with the button at the
bottom left of the window.
Notes
LESSON 6 – GX Works2 Utilities
Page 80
Divide by zero causes an error number 4100. So 4100 is the error number that
appears in register SD0.
Double click on an active error to see more detailed error information. This is the
information found in SD1 through SD26.
Click on the Error Jump button in PLC Diagnostics to move the ladder diagram to
the instruction responsible for the error. The divide operation is highlighted in red.
This is the instruction (step 3) that is faulting out. While we could guess this in a
small program such as this, it is very handy for large programs.
Notes
LESSON 6 – GX Works2 Utilities
Page 81
Click on the Help button in PLC Diagnostics for more information on the error
message. A help screen for the selected error should appear. The following
screen should appear for the 4100 error.
This screen explains possible
causes of the error state and
possible solutions. While
divide by 0 isn’t explicitly
stated here, it does indicate
that there are references to
data which cannot be
processed by an instruction.
Any errors which can be
caused by PLC code indicate
the possible errors and their
causes in the section for each
command in the Q/LSeries
Programming Manual
(Common). This information is
also now available from the
Help menu in GX Works2.
By looking up the divide instruction in the manual or help file, we can see that the
only reason for a divide instruction to create a 4100 error is a divide by zero.
GX Works2 has error help screens for most CPU error codes. If the selected
error has a help screen, it will be shown automatically when the Help button is
pressed. Detailed PLC error code information is also found in the Help menu. A
complete list of error codes and their details is found here.
More detailed information on the error numbers and their causes is detailed in
the appropriate programming manual. This information is also available in the F1
help for the command.
Notes
LESSON 6 – GX Works2 Utilities
6.5
Page 82
System Monitor
The system monitor screen provides a snapshot of key information about the
system. Data such as the module part numbers, module types (input, output,
special function modules, etc.), space occupied, and addressing are available.
The top half of the system monitor window shows a pictorial of the connected
controller based in the information read in from the units. Above each module is
its starting address, as well as a symbol to indicate module status as shown in
the legend in the bottom left corner.
By clicking on any module in any base, the Operation to Selected Module section
in the upper right will be updated. Depending on the module type, there are 4
buttons which may become available. These buttons offer detailed module
information, hardware information, diagnostics, or module error history. The
bottom left of the system monitor shows the number of installed modules.
Notes
LESSON 6 – GX Works2 Utilities
Page 83
The bottom right of the system monitor shows parameter allocation and module
head addresses. This is settings made in the PLC parameters, or automatic
allocation if parameters were not set.
6.5.1 Module Detailed Information
GX Works2 has built-in screens which will provide a more detailed look at
a particular module. The information that appears on this screen will vary
according to the type of module selected. Some of the information shown
on the screens for all modules would include:
•
•
•
•
Module name (part number)
I/O address
Location within the extension bus
Serial number (if available)
The detailed information for the module can be accessed from the
‘Detailed Information’ button or by double clicking on the module in the top
half of the System Monitor screen.
Notes
LESSON 6 – GX Works2 Utilities
Page 84
This screen capture is from an input module. It gives the status of the
power supply, fuses, and whether or not the module address is in
agreement with the I/O Assignment Table, if it is used. Since this is an
input module, which has an adjustable response time, this setting is
displayed as well (Noise Filter Setting). Input and output cards do not
have onboard diagnostics and error tracking, so the error information
section is grayed out. No product information is provided as this electronic
serial number is not part of an I/O module.
Notes
LESSON 6 – GX Works2 Utilities
Page 85
Other modules, such as intelligent modules, offer even more information.
Intelligent modules have an electronic serial number, which shows in the
upper right module information box. Intelligent modules also offer their
own on-board error monitoring and history. This is shown in the bottom
half of the window. The screen below is for an analog input module.
Notes
LESSON 6 – GX Works2 Utilities
Page 86
6.5.2 Product Information List
This provides a snapshot of the connected hardware. Some of the useful
troubleshooting data includes module rack location and configuration,
occupied space, starting address, electronic serial number (if present in
module), and product revision info. This screen is available from the
‘Product Information List’ button on the bottom right of the System Monitor
screen.
What makes this screen especially useful is that by clicking the ‘Create
CSV File’ button in the lower left corner, this information can be exported
into an Excel spreadsheet and used for documentation or sent out for
analysis.
Notes
LESSON 6 – GX Works2 Utilities
6.6
Page 87
Sampling Trace
Sampling trace is a diagnostic function available in the L Series and Q Series
processors (except the basic models). This utility is used to log data over time
when something happens in the program. The data is stored inside the CPU, so
there is no time delay for communications. Data trace executes completely in the
CPU, and then the results can be uploaded.
This tool can be used to trace up to 8192 samples of 50 bits and 50 words in the
High Performance and Universal Q CPUs (except Q00UJCPU) or L Series CPUs.
To start the utility, go to the Debug menu, select Sampling Trace, and then Open
Sampling Trace. The following screen is displayed.
Once the sampling trace window is open, the sampling trace toolbar will be
shown, and several new options are added to the Sampling Trace option in the
Debug menu.
Notes
LESSON 6 – GX Works2 Utilities
Page 88
The first thing to do after opening the sampling trace screen is configure the trace.
This can be done with the toolbar button or Selecting the Debug menu, then
Sampling Trace, and then Trace Setting.
On this first tab, the choice is given to create new trace settings or use the trace
settings in the current connected PLC. The location to store the data is also
selected, and the filename for storage. In the Q Series, the data file can be
stored on a RAM memory card. On L Series. iQ Series, and Q processors with
serial numbers beginning with 07032 or newer, the Standard RAM drive can be
used instead of a memory card.
On the Condition Setting tab, the trace is configured. The number of samples,
after trigger samples, additional information to log, trace point setup and trigger
point setup are configured.
Notes
LESSON 6 – GX Works2 Utilities
Page 89
Trace Count Settings configure the number of samples to store, and how many
of those samples are stored from before the trigger signal was received.
Additional Information adds information to each entry in the sample trace.
Data Acquisition Timing Setting sets the frequency of the data collection. The
choices are each PLC scan, specified time intervals, or detail settings. Detail
setting allows selection of an address and the criteria to be met by that address,
such as rising or falling edge of a bit, or a word equal to a specified value.
The Trigger Condition Setting section allows the configuration of the trigger
signal. This trigger signal can be set to the TRACE instruction execution in the
PLC program, manually triggered from GX Works2, or detail settings for an
address. The detail setting section is the same as for the timing section, allowing
bit or word addresses.
In the top half of the sampling trace window, register the addresses to be logged
by entering values into the Device/Label column. Items can also be added to the
trace by dragging and dropping them in from the ladder window when the
sampling trace window has been opened.
If the trace is to be started from conditions in the PLC and not from GX Works2,
the trace configuration must be registered to the PLC. Select the Register Trace
option from the Sampling Trace menu in the Debug menu. If the trace will be
started from GX Works2, select Start Trace.
Notes
LESSON 6 – GX Works2 Utilities
Page 90
Once the trace has been registered to the PLC,
a window will appear which shows the current
trace buffer status. On the left will be a picture
of the storage location and the filename
selected for the storage data. Once started, the
total data bar will begin to move. If the trace is
not going to be monitored online, then this
window can be closed. It can also be displayed again with the ‘Display Trace
Buffer Condition’ option in the menu or on the toolbar.
Once the trigger signal has been received, the
data after trigger bar will begin to move. Once
this bar reaches 100%, the data will be
uploaded and displayed in the sampling trace
window.
Each column on the upper right side of the
window will indicate a sample of the data. Bit data will show as a line going up or
down to indicate on or off. Numeric data will show crossed lines each time it
changes.
Samples can be viewed by moving the scrollbar at the bottom of the window left
or right. The yellow bar is the cursor, and it can be moved with the arrow keys.
The values shown in the Vertical Axis column are the values at the cursor.
Notes
LESSON 6 – GX Works2 Utilities
Page 91
GX Works2 also has the ability to perform trend graphing of the numeric data.
To add numeric data to the graph at the bottom of the screen, check the box in
front of the address in the top window. This will add a line to the graph in the
bottom window. The color of the line can be changed by double clicking on the
colored box at the start of the line.
If the trace was executed while the PLC was not connected to the PLC, then the
data must be uploaded from the PLC. This can be done from the Sampling
Trace menu.
Once the data is in GX Works2, it can be easily exported to a .CSV file for
reference in other applications like Microsoft Excel. This is done from the
Sampling trace menu.
To erase the settings and start over, select Delete All Data from the Sampling
Trace menu. Changing the sampling trace configuration will erase the trace data
already in GX Works2.
Notes
LESSON 6 – GX Works2 Utilities
6.7
Page 92
EXERCISE – Sampling Trace
Load the program from Lesson 4 back into the CPU.
Configure a sampling trace with the following settings:
•
•
•
•
•
Bit Addresses
o M0
o M1
o Y10
o Y11
o Y12
o Y13
Words
o T0
o T1
o T2
o T3
o T4
o T5
o D3
o D4
o D5
Trigger point should be bit M0 turning on
Take 200 samples at 100msec intervals
Samples before trigger should be set to 10
This will provide 20 seconds of sample data, with 1 second of data stored from
before the trigger is activated. Execute the program by pressing M0 and view the
trace results.
Notes
LESSON 7 – Special Addresses
Page 93
LESSON 7 – Special Addresses
This lesson introduces the special relay and special register areas of the L Series
processors.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Understand the function of SM and SD memory areas.
• Write code utilizing diagnostic information in the ladder program.
The L Series has a dedicated area of memory with useful system information. There
are both bit and word addresses which are controlled by the CPU.
7.1
Special Memory Bits
Special memory bits are in a separate memory location in the L Series
processors. The basic layout of these addresses is identical to the Q Series.
The SM bits are listed in Appendix 3 of the MELSEC-Q/L Programming Manual
(Common Instructions). The complete list is also available in the online help
menu in GX Works2. These relays can be useful when developing your ladder
program, and developing diagnostics within your program.
Some of the most commonly used contacts are:
•
•
•
SM0 General Error Flag
SM52 Battery Low
SM60 Fuse Blown
Any PLC Error
PLC battery under 2.4V
Bad fuse or I/O module power problem
Some bits which are not diagnostic related are:
•
•
•
•
Notes
SM400
SM401
SM402
SM403
Always ON
Always OFF
On for First Scan only, then off
Off for First Scan only, then on
LESSON 7 – Special Addresses
Page 94
There are some free running clock pulses in the CPU as well. These can be
used for timed operations, such as flashing a warning light on an output. Each
pulse is on for the specified time and then off for the same amount of time.
Two additional free running clocks have a user-defined pulse length. The length
of time to run is adjusted in the SD register of the same address (SD414 or
SD415). The bit will remain on for the specified time, and then off for the same
amount of time.
As an example, if SD414 is set to 10, SM414 will be on for 10 seconds, then off
for 10 seconds, and will repeat constantly.
Notes
LESSON 7 – Special Addresses
7.2
Page 95
Special Registers
Similar to the special relays, there are a large number of special registers that
hold diagnostic and parameter information about the CPU. Information on these
registers is in the MELSEC-Q/L Programming Manual (Common Instructions) in
Appendix 4. The complete list is also available in the online help menu in GX
Works2.
Whenever a fault occurs in the CPU, the ERROR LED on the CPU module will
illuminate. The error will not necessarily cause the ladder program to stop
executing, although it may. This action is dependent on settings in the PLC
parameters.
There are 27 dedicated D registers that hold critical information regarding faults.
•
•
•
•
SD0 General PLC Error Code
SD4 Error Code Type Information
SD5-SD15 Common Error Information
o Contents vary by type of error
SD16-SD26 Individual Error Information
o Contents vary by type of error
Some of the most common errors are:
•
Notes
1600 Battery Error
o This error occurs when the CPU module battery drops below 2.4
volts. The battery is a 3.6V battery; however it typically measures
around 3.69VDC.
o This fault occurs at initial power up of the unit because the battery
is disconnected from the factory so it will not discharge while on the
warehouse shelf. The battery is mounted on the inside of the
maintenance door, on the bottom of the CPU module.
LESSON 7 – Special Addresses
Page 96
•
2200 Missing Parameter File
o The parameter file holds such information as the type of I/O
modules, the amount of memory devices, time bases, etc. Without
it, the CPU cannot function.
o The error is usually the result of forgetting to download the
parameters when downloading the program
•
2500 Can’t Execute Program
o Typically occurs when a PLC parameter issue is present. This
could be a program in the CPU which is not referenced in the
Program tab of PLC Parameters, or a missing program file.
•
3300 Special Parameter Error
o This error is caused when intelligent module parameters exist in the
CPU for modules which do not exist on the controller, or if the head
addresses of the modules in the intelligent module parameters do
not match the connected PLC.
•
4100 Operation Error
or
4101 Operation Error
o This error results when an instruction executes in an illegal mannerusually due to a programming error.
o Typical examples are a divide by 0, BCD conversion on a number
that is too large, etc.
o When the instruction that is causing the error is discovered, good
practice is to consult the programming manual description for the
instruction. Each instruction description has a troubleshooting
section detailing common errors.
There are many other possible error codes. These codes, with descriptions and
suggestions for possible causes, are listed in Chapter 12 of the MELSEC-Q/L
Programming Manual (Common Instructions).
Notes
LESSON 7 – Special Addresses
7.3
Page 97
Troubleshooting Examples
7.3.1 Battery Low Warning Indicator
Since the PLC battery low indicator LED is on the CPU, and since the
CPU is typically inside of a control cabinet where it cannot be seen, it is
sometimes desirable to have an external indication. To do this, and output
can be connected to the low battery warning bit.
Now when the battery low alarm happens, output Y10 will be energized.
7.3.2 PLC Error Code Backup
Typically, when the power is removed from the PLC, the contents of the
diagnostic registers are cleared. Many times the first test performed when
a PLC is not functioning properly is to power off and reset the PLC. This
will result in the loss of the active error code number and information if the
error is not still active when power returns.
To ensure the data is backed up, we can use file registers. As previously
discussed, file registers are retentive. So removing the power from the
CPU will not clear this information.
To do this, we will monitor for the error code 4100 in SD0, and then use
the move instructions covered previously to move the error information to
file registers.
Notes
LESSON 7 – Special Addresses
7.4
Page 98
Real Time Clock
All Q and L Series processors have a built-in real time clock. This clock is
backed up by the PLC battery, and so will maintain its value through power loss.
The clock is accessible in special data registers SD210-SD213 in BCD format.
Each byte of the register is used to store a different piece of the real time clock
data. It is easier to access the clock using dedicated commands.
The DATERD command will read the 4 words of clock data and break it down
into 7 consecutive data registers. DATERD requires one parameter, the first of
the 7 addresses to store the clock data.
The same 7 registers can be written back to the CPU clock using the DATEWR
instruction. It also takes one parameter, which is the first of the 7 addresses
containing the data to be written to the clock.
This data can be used for such applications as time stamping of data tables,
comparison instructions for time of day operations, or display on an operator
interface.
Notes
LESSON 8 – Intelligent Modules
Page 99
LESSON 8 – Intelligent Modules
This lesson covers the methods used for communication with intelligent modules.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Identify intelligent modules.
• Write instructions to send/receive data to/from a module.
• Use direct addressing to access data within intelligent modules.
• Understand the application of the Intelligent Module Utility.
8.1
Intelligent Module Introduction
Any module which is not a discrete input or output module is considered an
intelligent module. Intelligent modules are used by the controllers in a different
way than regular I/O modules. The intelligent modules all have internal memory
and perform a higher level hardware function outside of the PLC’s typical scan
cycle. They are constantly updating data stored within the module.
Communication with these modules can be done one of several ways.
To understand the way the PLC sets allocation of these modules is important.
Intelligent modules do still occupy I/O addresses. Depending on the card, it may
require 16 bits or 32 bits. The module may make use of both inputs and outputs
in these addresses. So if the head address of the module is 0020 and it
occupies 32 bits, the module is assigned X20-X3F and Y20-Y3F.
The use of each of these I/O points varies by module. The purpose of the I/O
points is detailed in the manual for each module. The table on the next page
shows the input and output allocation for the L60AD4 Analog Input Module. The
addresses marked as ‘use prohibited’ should not be accessed within the program.
Notes
LESSON 8 – Intelligent Modules
Page 100
There is no automatic transmission of data from or to the intelligent modules.
Instead, intelligent modules have a series of buffer memory locations within the
module’s internal memory. The function of each buffer memory location varies
by module. The purpose of the buffer memory locations is detailed in the manual
for each module. Below is a section of the list for the L60AD4 module.
These locations work like mailboxes, storing the data for the module. The data is
accessed by reading or writing from or to the buffer memory location.
Notes
LESSON 8 – Intelligent Modules
8.2
Page 101
TO/FROM Instructions
The method used to read or write data to buffer memory locations on intelligent
modules is identical no matter which type of intelligent module is being used.
There are dedicated instructions in the CPU for reading data from a module or
writing data to a module.
The FROM command is used to read data from an intelligent module. The TO
command is used to write data to an intelligent module.
These commands can be coded in ladder, structured ladder, or structured text.
Examples of each are shown below. The commands shown below will all read 5
words of data from the module at address 30, starting at buffer memory 100, and
place the results in 5 registers starting at D100.
Structured Ladder
Structured Text
Ladder
Notes
LESSON 8 – Intelligent Modules
Page 102
In the ladder programming language, the commands are coded using the
standard square brackets.
The FROM instruction retrieves data from one or more sequential buffer memory
locations and stores it into consecutive data registers in the CPU.
The TO instruction sends data from one or more consecutive addresses in the
CPU memory to consecutive buffer memory locations in the intelligent module.
When the data designated as the source (S) is a fixed numeric value, that
numeric value is written to all of the destination addresses.
Notes
LESSON 8 – Intelligent Modules
Page 103
In the structured programming languages, these instructions are coded in a
slightly different way. Parameters all have the same designators (n1, n2, n3, s,
d) and still serve the same functions, but are input in a different order.
Notes
LESSON 8 – Intelligent Modules
8.3
Page 104
U\G Addresses
In newer controllers, such as the Q Series, L Series, and FX3U, there is a direct
access method for reading and writing to buffer memory locations with standard
commands. Instead of using TO and FROM, a special address allows most 16bit or 32-bit word commands to access buffer memory.
The U\G address consists of 2 parts.
•
•
The U number is the head address of the module (without the 0 on the
end, just like the TO or FROM instruction).
The G number is the buffer memory address (in decimal).
So the ends result of the two commands below is the same:
•
•
FROM H4 K20 D0 K3
BMOV U4\G20 D0 K3
These 2 commands are also identical:
•
•
TO H7 K15 D10 K1
MOV D10 U7\G15
The U\G addresses actually operate slightly faster than TO and FROM
instructions. But each time the U\G addresses are used, the data is read. So
using the same U\G address several times will in fact be slower than using a
FROM instruction and then referencing the data registers which it was stored to.
Notes
LESSON 8 – Intelligent Modules
8.4
Page 105
Intelligent Function Utility
For the L Series, GX Works2 offers an intelligent function module utility designed
to simplify the process of communication with intelligent function modules. There
are many types of intelligent function module utility available.
ƒ
ƒ
ƒ
ƒ
ƒ
Analog Modules
High Speed Counters
LD75 Positioning Modules
Serial Communication Modules
Simple Motion Modules
In GX Works2, these utilities are accessed by adding an intelligent module into
the Intelligent Function Module folder in the project navigation tree. To do this,
right click on the folder and choose New Module. The screen below will be
shown.
The top list shows the various configuration utilities available in GX Works2. Any
of these modules can be configured without writing logic with this utility. Once
the module type is selected in the top window, the modules offered within that
type are selected in the second box.
Notes
LESSON 8 – Intelligent Modules
Page 106
The middle portion of the window is used to configure the location of the module.
It can be configured via the slot number or the starting I/O address of the desired
module. The Acknowledge I/O Assignment button shows the PLC layout as
configured in the PLC Parameters for easy selection.
The title setting is a method of documenting the function of this module. It is not
required that this field be filled in.
Once the module is added, the settings for that card
can be adjusted by clicking the [+] next to the module
to reveal the configuration options. Different modules
will offer different options. These are intelligent
module switch settings, parameters, and automatic
refresh data.
The switch setting option allows
the adjustment of the software
switch settings. Software switches
were used in the L Series in place
of physical DIP switches for
module configuration. By storing
these in the PLC parameters
instead of on the modules,
replacement of a damaged module
is easier.
Settings are chosen in the
selection dialog, and when
finished, the software switches for
that module are updated in the
PLC parameters. Shown here is
the switch setting screen for the
L60AD4 analog input module.
Each module’s options will be
different.
Notes
LESSON 8 – Intelligent Modules
Page 107
Parameter is the window where configuration information about the module is
modified. This window opens into the tabbed workspace on the right side. Each
module’s options will be different. Help for the currently selected setting is
always shown across the bottom of the window. Shown here are the parameters
for an L60AD4 module.
For this analog module, configuration for all 4 analog input channels is shown.
Channels can be enabled or disabled, configured for sampling or averaging, and
number of times to sample or samples over a time period. This module also
offers a built-in scaling function, configurable at the bottom of the columns.
Notes
LESSON 8 – Intelligent Modules
Page 108
Auto refresh allows the data from the module, such as analog input values,
maximum and minimum values, and module error code can be automatically sent
to addresses in the CPU. Shown here is the L60AD4 module. Clicking in any of
the boxes will allow the PLC address of this data to be edited.
When performing a cross reference on one address or the entire project,
addresses used in the intelligent module utilities will show as used. Which
module they were used in can be determined from the cross reference window.
Devices used in the automatic refresh tab will show as used with an asterisk in
the parameter column of the Device List window.
Notes
LESSON 8 – Intelligent Modules
Page 109
When downloading to the CPU, there will be a new check box for the intelligent
function module parameters. Under the Parameter section, this option is called
‘Intelligent Function Module’. Check this box to send the intelligent module
parameters to the PLC.
It is important to note that if intelligent module parameters were sent to the CPU
and then cards are reordered or removed, the parameters must be updated or
deleted. The PLC will fault with a parameter error if parameters are set for a
module which does not exist, or the wrong module type at a starting address.
Notes
LESSON 8 – Intelligent Modules
8.5
Page 110
EXERCISE – Intelligent Module Access
An L Series controller has the following modules installed.
L26CPU-BT, L60AD4, D60DA4
Write the TO/FROM instructions or logic using U/G addresses to accomplish the
following:
The L60AD4 has 4 analog inputs. The analog inputs will be a value from
0 to 20,000 indicating a voltage reading of 0 to 10VDC.
•
Read the 4 values into the CPU and store them in D100 through
D103.
•
Read the error code information from the module and store it to
D105.
The L60DA4 has 4 analog outputs. These outputs are a numeric value 0
to 20,000 to cause an output of 0 to 10VDC.
Notes
•
Write the PLC code to limit the output data in D120 through D123 in
the CPU to the range of 0-20,000 and then output the limited values
to the analog output module.
•
Read the error code from the module into D125.
LESSON 9 – PLC Parameters
Page 111
LESSON 9 – PLC Parameters
This lesson explains the configuration of PLC operation using the PLC parameters.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Understand the use of the PLC parameters function.
• Configure CPU operation settings.
• Create I/O assignment and configure I/O modules.
9.1
PLC Parameters
PLC configuration parameters are specific to the project, and are stored with the
GX Works2 project. Parameters adjust such things as the operation at error, I/O
assignment, memory allocation, and file storage.
To access the PLC parameters, click on the [+] next
to Parameters in the project tree, and then double
click on PLC Parameters. Network parameters are
found in the same place, in a subfolder called
Network Parameter.
The color of the text on the tabs in PLC Parameters
is important. If the text on the tab is pink, no
settings on that tab have been changed from defaults. If the tab color is blue,
settings have been made on that tab.
On the bottom of each tab is a button labeled ‘Default’ which will set only the
settings on that one tab to the factory defaults.
Parameters can be printed with the Print button on the bottom of the parameter
tabs. All parameters are printed no matter which tab is open.
Notes
LESSON 9 – PLC Parameters
9.2
Page 112
PLC Name
The PLC Name tab allows the programmer to assign a label and a comment that
helps to define the application of this program. This information is stored with the
project in the CPU.
The Label setting is useful when working with the L Series and Q Series
processors with built in Ethernet. The label is shown in the Connection dialog
when searching the network for available CPUs with built-in Ethernet.
Notes
LESSON 9 – PLC Parameters
9.3
Page 113
PLC System
The PLC system tab deals with basic configuration parameters for the CPU. The
two most common changes on this tab are the time bases for low speed and high
speed timers and the points occupied by an empty slot.
Timer limit setting configures the time base for low speed and high speed timers
as discussed earlier.
The RUN and PAUSE signals allow any PLC input to be defined to work as a run
switch or pause switch.
The latch data backup operation is used to set a contact address to backup
latched memory areas to standard ROM before powering down the CPU for
extended amounts of time.
Notes
LESSON 9 – PLC Parameters
Page 114
Remote reset must be checked if software reset of PLC is to be allowed. By
default, this feature is disabled for safety reasons.
At the bottom of the first column is a check box to enable the built-in CC-Link
module on the L26CPU-BT. By default this is on, but if the module is not to be
used, it can be turned off here to prevent error detection.
Common pointer setting is used to set a range of pointer addresses to be local to
specific programs. By default all pointers are global.
Points occupied by an empty slot sets the default I/O allocation for all empty slots.
System interrupt settings configure the time interval for timed interrupts.
Notes
LESSON 9 – PLC Parameters
9.4
Page 115
PLC File
The PLC file tab allocates storage locations for data which is not automatically
allocated in the CPU. Each option is assigned a location and file name to store
the data.
File register allocates memory for storage of file registers either on the internal
Standard RAM drive. L Series defaults to 128K of data registers in a file called
MAIN. There is a check box to include file registers in the latch data backup
discussed on the last tab.
Comments used in command allocates storage location for comments which will
be accessed by commands within the CPU. Initial device value sets a location to
store initial values to be loaded into data registers at power-up. File for local
devices is used when local devices are configured to store the multiple instances
of the address. File used for SP.DEVST/S.DEVLD sets a file to be used by these
two special commands in the CPU.
Notes
LESSON 9 – PLC Parameters
9.5
Page 116
PLC RAS
RAS is an abbreviation for Reliability, Accessibility, and Serviceability. This tab
configures the PLC watchdog timer and error handling.
Watchdog timers are used to warn if the processing of the program is taking too
long. There are different watchdog timers for standard scan and initial scan
programs.
Operating mode when there is an error sets whether the CPU will continue or
stop in the event of several different types of CPU errors.
Error check will allow certain types of error checking to be turned off completely.
Constant scan sets a fixed execution time for each PLC scan.
Module error history collection will allow the errors detected by the intelligent
function modules to be browsed in the PLC’s main error history.
Notes
LESSON 9 – PLC Parameters
9.6
Page 117
Boot file
The boot file tab is used to set the locations to copy various components of the
CPU configuration and program at startup. This is typically used when the data
is stored on a separate memory card or in the Standard ROM drive.
Each item to be copied to the CPU’s memory is added to this list. When the PLC
is powered up and a boot file exists on the memory card or Standard ROM drive,
the settings made there will be followed prior to starting the CPU into the RUN
mode.
Notes
LESSON 9 – PLC Parameters
9.7
Page 118
Program
The program tab sets up the program type and execution order when using
multiple programs. With GX Works2, this can also be done by drag and drop of
the programs into the Program Setting section of the project navigation window.
9.8
SFC
The parameters on the SFC tab are used to configure basic operation of
programs written in the Sequential Function Chart programming language.
SFC programming is covered in the iQ Works Structured Programming class. It
is outside the scope of this class.
Notes
LESSON 9 – PLC Parameters
9.9
Page 119
Device
The Device parameters tab allocates memory to various data types in the CPU,
and sets the battery backed ranges of addresses.
The dev point column configures the quantity for each type of data memory. This
number is set in single numbers or by K (1024) addresses. The number of
addresses configured for each memory type is adjustable. Below the table, the
window shows the total memory used. This value must be 29K or less. It may
be required to lower one address quantity before raising another to maintain this
29K limit.
Notes
LESSON 9 – PLC Parameters
Page 120
Latch 1 and Latch 2 start and end set the first and last addresses in a range
which are backed up by the battery. Latch 1 range can be cleared with the latch
clear function, while Latch 2 cannot be cleared.
The local device starting and ending addresses set a range of addresses which
will be unique to each program. For example, if 0 and 10 are entered in the D
row, D0 through D10 will be unique within each program, so values written to D0
in one program have no effect on D0 in another program. This is useful to set
local addresses when multiple programmers will write different sections of the
program. It will allow a range of addresses to be specified which have no effect
on the other programs.
The bottom half of the Device tab is used to allocate the file registers to various
memory addresses. If file registers are allocated and configured on the PLC File
tab, this section will allow distribution of that memory across D, R, and W
addresses. The default allocation of the 128k of file registers is that file registers
become addresses D12288 through D143359. The 128k can be divided into R
registers, W registers, and D registers as the programmer sees fit.
Notes
LESSON 9 – PLC Parameters
Page 121
9.10 I/O Assignment
The I/O assignment tab serves many purposes. On this tab, the allocation of the
modules can be configured. Other settings such as input filter, output mode at
stop, and software switch settings for intelligent modules can be configured.
Settings are not required by default, as the CPU will automatically read the
connected modules and allocate addressing at power-up. In order to configure
settings such as input filter or software switch settings for intelligent modules, this
information needs to be configured.
There is a button at the bottom to read the currently connected controller’s I/O
and configure the table to match this information.
Notice on the L26CPU-BT (shown above) 2 modules have already been
allocated. The first module is the built-in I/O points, and the second is the built-in
CC-Link module.
Notes
LESSON 9 – PLC Parameters
Page 122
The top half of this window is used to configure the module types and their
starting addresses.
¾ The type column allows choice of module type. Choices are empty, input,
output, and intelligent.
¾ The model name column is for documentation only. Typically the part
number of the module would be entered here.
¾ The Points tab sets how many addresses are allocated to a module.
¾ The StartXY column sets the head address of each card in the base units.
This setting is not required, but does allow the L Series to apply addresses
out of order.
Clicking the Switch Setting button will bring up access to the software switch
settings page. This information is a software replacement for the various DIP
switches which used to exist on the front of many of the modules in the A Series.
Instead, software settings are made and stored in the CPU, which makes
replacement of a failed module much easier. All switch settings are stored in the
parameters which are stored in the CPU.
Any module configured as intelligent will have 5 software switches, each of which
is a 4-digit hexadecimal value. Modules which are not intelligent will be grayed
out. The setting for each switch and their purpose varies by module, so it is
important to have the documentation for the intelligent modules available when
configuring these switch settings.
These switch settings can also be made in the intelligent module utility.
Notes
LESSON 9 – PLC Parameters
Page 123
The Detailed setting button allows for configuration of the discrete I/O modules.
For input modules, the input response time can be configured. This value is
independently configured for each input card.
Output modules allow the setting of the status of the outputs, which allows the
CPU to leave certain outputs on in the event of a CPU error.
Intelligent modules also offer error time output setting. An additional option for
hardware error PLC operation allows the programmer to determine if a hardware
error detected in this module will stop the processor or allow it to continue.
Notes
LESSON 9 – PLC Parameters
Page 124
9.11 Built-In Ethernet
With the L Series processors, there is another tab for configuration of the built-in
Ethernet port.
On this tab, the standard Ethernet settings like IP address, subnet mask, and
default gateway are configured. There are check boxes to allow online changes,
disable the direct connect to MELSOFT, and not respond to processor searches
on the network.
There are also buttons for configuring the open port settings, FTP access
settings, and SNTP time protocol configuration.
Notes
LESSON 9 – PLC Parameters
Page 125
9.12 Built-In I/O Functions
The L Series controller has 16 inputs and 8 outputs built in. These can be
configured for special functions in the Built-In I/O Function tab.
On the top left are 2 buttons to configure the 2 axes of built-in pulse output
positioning control. Next to those are 2 buttons to configure the 2 channels of
high speed pulse input.
The bottom half of this window can be used to allocate specific functions to
specific inputs or outputs. The choices are limited based on each address, and
many require settings to be made using the 4 buttons above to be valid.
Inputs can be configured for general, interrupt, or for signals related to the high
speed counter inputs or pulse outputs.
Outputs can be configured for general, or for signals related to the high speed
counter inputs or pulse outputs.
Notes
LESSON 9 – PLC Parameters
Page 126
9.13 Network Parameters
With the L Series, CC-Link networks are configured with parameter settings.
This includes the built-in CC-Link module of the L26CPU-BT.
Network parameters are found in the Parameters section of the project tree,
directly under the PLC parameters.
The screen shown below is for CC-Link. Each column is used for an additional
CC-Link module. Up to 2 cards can be configured on L02CPU, with 3 cards plus
the built-in CC-Link available on the L26CPU-BT.
Configuration and operation of CC-Link are covered in the CC-Link Networking
training class.
Notes
LESSON 10 – Label Programming
Page 127
LESSON 10 – Label Programming
This lesson will cover the basics of label programming in GX Works2.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Understand the difference between global, local, and system labels.
• Assign labels and write programs using labels.
10.1 What are Labels?
Labels are a method of assigning a name to an address or variable in the
controller. This label can be used in place of the physical address when writing
code. Assignment of labels is required when using the structured text
programming language, and is optional in the other languages.
There are several types of labels in GX Works2. The 2 most common types are
global and local labels.
•
•
Global labels are registered in the Global Label list in the project
workspace, and apply to every program created within the project.
Local labels are registered under the program in the POU section of the
project workspace, and apply only within the specific program.
Labels are also used with functions and function blocks, and for creating
structured data types.
•
•
Function block labels are used inside function blocks, and identify the
input and output connections on the function block.
Data structures, such as arrays and structured data types, can be created
by using labels.
More information on labels can be found in Chapter 5 of the GX Works2
Operating Manual (Structured Project).
Labels are also sometimes referred to by other vendors as tags or variables.
Notes
LESSON 10 – Label Programming
Page 128
The labels are configured through the following sections of the navigation window.
Notes
LESSON 10 – Label Programming
Page 129
Labels can be up to 32 characters long. Some basic rules to follow are:
•
•
•
•
Labels cannot include spaces
Labels cannot begin with a number
Labels cannot be the same as device numbers, such as M1
The following characters are not allowed in labels
/\*?<>|“:[];,=+%‘[email protected]{}!#$&
A complete list of unusable labels can be found in Appendix 9 of the GX Works2
Operating Manual (Common).
10.2 Registering Global Labels
Global labels are registered in the Global Label section of the navigation window.
There are 2 classes of label which can be registered.
•
•
VAR_GLOBAL items are common labels which can be used in all
programs and reference an address in the PLC memory.
VAR_GLOBAL_CONSTANT is a label specified for a constant number.
After the class is chosen, the label name is entered, following the rules
mentioned before.
Using the right click menu or the Edit menu, options ‘New Declaration (Before)’ or
‘New Declaration (After)’ allow entries to be added before or after the currently
selected label. New Declaration (After) will increment the label and address and
set all other settings identical to the selected label. This is handy for creating a
series of consecutive label names.
Notes
LESSON 10 – Label Programming
Page 130
The data type can be selected from a list by pressing the […] button to the right
of the data type column. The dialog window below allows the selection of a
simple data type, structured data type, or function block data type.
Structured data types and function block data types are displayed based on the
subjects configured within the open project.
If the VAR_GLOBAL_CONSTANT class was selected, the next column is used to
set the constant value for the label.
If the VAR_GLOBAL class was selected, the next 2 columns can be used to set
the address associated with the label. In the Device column, a Mitsubishi
address can be defined. In the Address column, and IEC compliant address can
be defined. The Address column only exists in structured projects. Only one of
the columns needs to be filled in, the other will be filled automatically. These
fields can be left blank and an address will be assigned automatically. If the data
type is a structure, these columns will contain buttons labeled ‘Detail Setting’
which will display a configuration window when clicked with the mouse.
The last 2 columns are for documentation. Comments can be displayed with the
addresses in the program window, just as they were in GX Developer. Remarks
are additional documentation space which can be up to 1024 characters.
Notes
LESSON 10 – Label Programming
Page 131
10.3 Registering Local Labels
Local labels will exist only within the program where they are created. They are
registered in the Local Label list inside the program in the POU section of the
navigation window.
The columns and options are very similar to the global labels.
The 3 classes available for local labels are:
•
•
•
VAR for a label to reference a PLC address
VAR_CONSTANT for a constant numerical value
VAR_RETAIN for a label which is latched
o VAR_RETAIN is not supported on the FX controllers.
The label name, data type, and constant fields are the same as discussed with
the global labels. Local labels are not defined addresses, so the device and
address columns are not available. Local labels support comments, but do not
have a remark column.
Notes
LESSON 10 – Label Programming
Page 132
10.4 Automatic Assignment
Labels can be automatically assigned addresses, instead of entering a PLC
address on each label. When the label’s device and address fields are left blank,
they will be automatically assigned a PLC address from a configured pool of
reserved addresses.
The reserved addresses for automatic label assignment can be adjusted by the
programmer in the project. From the ‘Tool’ menu, select ‘Device/Label
Automatic-Assign Setting’.
The window which is displayed will vary based on which family of PLC was
selected.
By default, the upper portion of the device memory is reserved for the automatic
assignment. These values can be modified for each of the displayed address
types.
Notice that in the RETAIN areas, most memory areas are listed twice, with a (1)
or (2) after them. This pertains to the Latch(1) and Latch(2) ranges as specified
in the PLC parameters on the Device tab.
Notes
LESSON 10 – Label Programming
Page 133
10.5 Using Labels
To write the program with labels, simply code the label name instead of an
address when configuring symbols in the ladder logic.
In ladder and structured text programs, labels will have an auto-complete
selection window appear as the name is entered, and the label can be selected
from this list.
If a label is entered which is not defined, a dialog window like the one below will
appear allowing the programmer to assign that label. It can be assigned as a
local label in the current program, or as a global label.
Notes
LESSON 10 – Label Programming
Page 134
10.6 EXERCISE – Global Labels
Create a new simple project, and select to use labels.
Add the following entries to the global label list:
•
•
Bits
o Start_Button
o Stop_Button
o Good_Part
o Bad_Part
o Total_Reset
o Run_Lamp
o Conveyor
o Reject_Gate
Words
o Good_Count
o Bad_Count
(M0)
(M1)
(M2)
(M3)
(M4)
(Y0)
(Y1)
(Y2)
(D0)
(D1)
When the start button is pressed, the system will begin to operate, and the run
lamp and conveyor will turn on. The stop button will shut the system off.
Sensors Good_Part and Bad_Part are used to indicate a good or bad part on the
conveyor.
When a good part is detected, increment the good product count.
When a bad part is detected, increment the bad part count, and turn on the reject
gate for 3 seconds.
When the reset totals switch is pressed, reset the good and bad product counts.
NOTE: Addresses are only specified so the GOT screens will operate properly.
Notes
LESSON 11 – Structured Projects
Page 135
LESSON 11 – Structured Projects
This lesson will introduce the concepts involved with structured projects.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Understand what IEC 61131-3 does and does not define.
• Identify the different components of the structured project.
11.1 IEC 61131-3
IEC 61131-3 is an international standard related to PLC programming. It was
defined by the International Electromechanical Commission (IEC). It defines the
programming languages and structured elements used for writing PLC programs.
One of the basic goals of IEC 61131-3 is to create a uniform program structure
and naming convention for PLC programming. In this way, it is designed to allow
a programmer who is familiar with one brand of controls to program another
brand of controls with a very limited learning curve. A programming software
which is compliant should have the same basic look and feel, regardless of which
vendor's equipment the software is for.
It does not state that all software packages have to be identical, nor does it state
that code written for one vendor’s product should be able to be copied and
pasted into another vendor’s product. It simply lays out groundwork for a
programming method which would be similar among all vendors who comply.
Structured projects offer a different way of managing the programs in the PLC
than the simple projects.
Compliance with the standard is certified by PLCOpen. PLCOpen is an
independent third party who tests compliance with the standards and certifies
products as compliant to the standard. They also work to promote the use of IEC
61131-3 products.
Notes
LESSON 11 – Structured Projects
Page 136
The IEC 61131-3 standard defines 5 programming languages for users to create
their programs.
•
•
•
•
•
LD (Ladder Diagram)
FBD (Function Block Diagram)
SFC (Sequential Function Chart)
ST (Structured Text)
IL (Instruction List)
GX Works2 currently supports the LD, SFC, and ST languages.
The standards state that different components of a project can be written in any
of the various languages, and that a program is not locked into a single
programming language. The hierarchical structure of an IEC compliant project
allows for the programmer to organize the components of an application in an
intuitive format. It also makes the re-use of code easier.
The standards also allow for the assignment of names (labels or variables) to
identify devices such as I/O and data registers, allowing those names to be used
when writing code in place of the specific addresses.
A project is composed of several types of objects. These objects are referred to
as programs, tasks, and POUs (program organizational units).
Each project can contain multiple POUs. These POUs will be contained in
multiple tasks. Multiple tasks can be created and inserted into programs.
Notes
LESSON 11 – Structured Projects
Page 137
11.2 IEC Addresses
The IEC standard has a specified method for addressing of the PLC’s various
memory areas. The tables on the next 2 pages show the addresses in the
standard Mitsubishi format and the IEC compliant format. GX Works2 will allow
either type to be used, but use of the standard Mitsubishi style address makes a
program not compliant with the IEC 61131-3 standard
The basic explanation of the IEC addresses is shown here.
IEC addresses always begin with %. The next digit represents the memory
area. %I indicates input addresses, while %Q means output addresses. %M
indicates internal memory addresses.
The third digit indicates the size of the data. An X here means a bit address, a W
means a word address, a D indicates 32-bit double words. L indicates 64-bit
addresses, which are only available in the Universal model Q Series and L
Series CPUs.
Note that inputs and outputs are both referenced with an X. This X does not
indicate input like it does in standard Mitsubishi addresses. In IEC format, the X
is indicating a bit level address.
Notes
LESSON 11 – Structured Projects
The tables below shows the L Series addresses.
Notes
Page 138
LESSON 11 – Structured Projects
The table below shows FX Series addresses.
Notes
Page 139
LESSON 11 – Structured Projects
11.3 Structured Project
The components of a structured project are shown below.
Notes
Page 140
LESSON 11 – Structured Projects
Page 141
11.4 Program Organization Unit
The lowest level object in the program structure of an IEC compliant program is
the program organization unit, or POU. A POU is a segment of the program
code for the application. POUs can be written in any of the available
programming languages.
Instead of one large program like previous programming methods, a structured
project should be broken into smaller, more manageable POUs. This can make
troubleshooting much easier, as each POU can contain one small piece of the
complete program. A typical example is to segment the code for the program
based on the various sections of a machine. This way, only that section of code
needs to be reviewed when there is a problem with the machine.
There are 3 different types of POUs.
•
•
•
Program Blocks
Functions
Function Blocks
Most POUs are typically program blocks, which are executed based on the
configuration of the task which the program block is included in. Functions are
user-defined commands for use within other program blocks, functions, or
function blocks. Functions will only have one output type.
Function blocks are sections of code which can be called from within another
POU, and can be thought of as similar to subroutines. Function blocks can have
multiple outputs of various types or no outputs at all. Function blocks must be
assigned an instance name, since they have internal memory capable of storing
data between executions.
Functions and Function Blocks will be discussed in more detail later in this class.
Notes
LESSON 11 – Structured Projects
Page 142
POUs are created inside the Program Pool in the navigation window. Right click
on the Program folder under POU and select ‘Add New Data’ to create a new
POU. Or select Project, then Object, then New in the menus. The new POU
window below will be shown.
In this window, each POU is assigned a data type; Program Block, Function, or
Function Block.
Next the POU is assigned a name.
The last selection is the programming language to be used for this POU. Each
POU can be programmed in only one language, but multiple POUs can be
created using various programming languages within the same project.
Notes
LESSON 11 – Structured Projects
Page 143
11.5 Tasks
Tasks are used to execute the POUs created as program blocks. Multiple POUs
can be included within a single task, depending on the programming language
used.
The execution of a task can be based on PLC scan, a bit being on, or at a timed
interval. This is configured in the task properties screen, which is shown below.
To run this task as a constant scan program, the Event section should be set to
TRUE.
To use the interval function, set Event to FALSE, and set a time variable in the
Interval field.
Event can also be set to the on status of a bit. This bit can be a direct address
(like M0) or a label.
The time period for an interval task is set in the standard IEC time format, such
as t#1m for 1 minute, or t#15s for 15 seconds. This value should not be less
than the PLC scan time or it will not operate properly.
Notes
LESSON 11 – Structured Projects
Page 144
The Priority setting determines the order in which the tasks are processed by the
CPU. This is important in the event that more than one task is assigned the
same execution criteria, such as TRUE.
The lower priority numbers are executed first. When multiple tasks have the
same Event and Priority, they are executed in alphabetical order based on the
task name.
The title field is used to set a description for the task. A comment explaining the
purpose of the task can be added on the second tab of the new task window.
Some important rules for tasks are shown below.
•
•
•
A POU can only be registered into one task. Up to 320 POUs can be
registered to a single task. Up to 124 tasks can be created in a single
project.
Only one POU of basic ladder can exist in a single task. So each POU
coded in ladder (not structured ladder) must have its own task. Each task
of basic ladder must also be placed in its own program.
POUs written in SFC must exist in their own task. Multiple SFC blocks
can be placed in the same task, but that task must not contain any other
type of programs.
To attach POUs to a task, and to set the execution order of the POUs within a
task, right click on the task in the project tree and select ‘Open Task Setting’.
Register the POUs into this list in the order which they should be executed.
POUs can also be added to the task by clicking and dragging them into the task
in the navigation window.
Notes
LESSON 11 – Structured Projects
Page 145
11.6 Programs
Programs are used to group tasks. Programs are assigned an execution type.
Some of the reasons to create more than one program include:
•
•
•
Grouping of various tasks for a section of a system.
Security level settings can be made differently for each program.
Different program execution types, like initial scan or fixed scan, each will
require a separate program.
The end result of a properly configured structured program will resemble the
following layout.
Programs are then assigned to an execution type. This can be done in the PLC
Parameters in the Program tab. It can also be accomplished by dragging and
dropping the programs to a specific execution type within the Program Setting
section of the navigation window.
Notes
LESSON 11 – Structured Projects
Page 146
11.7 Compiling the Program
IEC 61131-3 programs must be compiled before being sent to the controller. The
compile process will convert the IEC commands and programming languages
back into the native instruction set of the PLC.
When programs exist which are not
compiled, they will be indicated in
RED in the project tree. Once
compiled, the names will turn black.
It is important to note that only
programs which are included in the
active tasks will be compiled. Any
POUs which are not included in
tasks, or any programs not
assigned an execution type will not
be compiled.
There are 3 options in the Compile menu in GX
Works2. Those items each compile a part of
the program.
•
•
•
Build can be used to build only uncompiled items. By only building the
components which are not already compiled, the time required can be
reduced.
Online Program Change will compile a program, check for errors, and if
there are no errors, update the PLC while it is running.
Rebuild All will recompile all programs used in the current project.
The results of the compile will be displayed as errors and warnings in the Output
window of GX Works2. Double clicking on one of these errors will navigate the
program window to the location of the error.
By default, the compiler will abort if the number of errors reaches 25 or the
number of warning reaches 100. These settings can be adjusted in the software
options, and the limit can range from 1 to 9999.
Notes
LESSON 11 – Structured Projects
Page 147
11.8 Symbolic Information
IEC programs are compiled into instruction list language which is used inside the
PLC. The PLC only requires this compiled version in order to run. Since that
code was compiled, the original program structure complete with labels and
program types does not exist inside the CPU.
For this reason, there is an option when writing to the PLC to include the
symbolic information. Symbolic information is the raw, uncompiled version of the
program. If the symbolic information was downloaded to the PLC, it can be
uploaded and the program languages and labels will be restored in the uploaded
project. Symbolic information is checked by default as part of the ‘Parameters +
Program’ button.
Symbolic information is typically the same size or slightly larger than the
compiled PLC programs, so this will require additional memory in the PLC. In the
Q Series, the symbolic information can be saved to the program memory or a
SRAM or ATA Memory Card. In the L Series, symbolic information can be stored
to the program memory, SD memory card, or Standard ROM. After checking the
symbolic information box, there is a selection to the right for the target memory
area. This does not need to be the same memory area which the program and
parameters are being downloaded to.
Notes
LESSON 11 – Structured Projects
Page 148
As previously discussed, when performing an online program change, a dialog
will ask to confirm the write while the PLC is running.
GX Works2 will check to see if symbolic information exists in the connected
controller when it performs and online write. If the symbolic information exists in
the controller, a prompt will be displayed asking if the symbolic information is to
be updated in the controller. If the symbolic information is not updated, the
executing program and the source code will not match, so it is advised that this
option always be used.
Notes
LESSON 11 – Structured Projects
Page 149
11.9 EXERCISE – Structured Project
In this exercise, you will create a new structured project, add programs and tasks,
and download to the CPU.
Create the first program in ladder (not structured ladder). Notice that a POU
called POU_01 is already created and added to as task, called Task_01. The
task is added to a program called MAIN. This all shows up under the ‘No
Execution Type’ folder in Program Settings. To make this a scan program, drag
and drop MAIN into the Scan Program folder.
Rename POU_01 to StartSequence. Enter the following code.
Create a new POU, called StopSequence. Enter the following code.
Notes
LESSON 11 – Structured Projects
Page 150
Create a third POU called Outputs. Enter the code below.
Since these POUs were all created in simple ladder, each one will need to be
assigned to a separate task, and each task must be assigned to a separate
program file.
Create 2 additional tasks and 2 additional programs and place one POU in each
task then place each task into the new programs. Try to compile the program,
and ensure that each program, POU, and task turns black and there are no
errors or warnings in the compile.
End result should be similar to this:
Download this project to the CPU, including the symbolic information.
Test the operation of the conveyor sequence.
Notes
LESSON 12 – Structured Ladder
Page 151
LESSON 12 – Structured Ladder
This lesson demonstrates the structured ladder programming language.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Identify the components of the structured ladder programming language.
• Write programs in the structured ladder programming language.
• Understand how timers and counters are used in structured ladder.
12.1 Introduction
Structured ladder is the IEC compliant ladder logic programming language. It is
only available in structured projects.
The standard IEC libraries and their functions are available to the programmer in
the structured ladder editor. There are also manufacturer-specific libraries, which
would contain comparable commands to the Mitsubishi-standard commands in
the ladder language.
Just like standard ladder, structured ladder relies on a power rail on the left hand
side. There is no displayed right hand power rail in structured ladder, it is implied.
Structured ladder is made up of contact and coils. Functions and function blocks
can also be called from within the structured ladder editor.
Ladder processes one block at a time, left to right, top to bottom, as shown below.
Notes
LESSON 12 – Structured Ladder
Page 152
12.2 Editor Basics
The structured ladder editor resembles the standard ladder editor in many ways.
It has a grid structure, and components can be placed anywhere along the grid.
Structured ladder is broken into ladder blocks. Only one rung of ladder logic can
be placed in each ladder block. To insert a ladder block, right click anywhere in a
ladder block, and select ‘Add Ladder Block Before’ or ‘Add Ladder Block After’.
The example below shows multiple ladder blocks, as well as contacts, coils,
functions, and function blocks.
Ladder blocks can be assigned labels (used for jump and subroutines) and a title
by double clicking on the gray block at the left side. Labels can be up to 8
characters, and titles can be 20 characters.
Notes
LESSON 12 – Structured Ladder
Page 153
In the Edit menu, there is a Ladder Block List, which will allow display of the
labels and titles of all ladder blocks. This is useful for quick navigation of the
POU contents, and offers insert, delete, cut, copy, and paste functions.
There are several options for the display format of the variables. By default, the
label name will be displayed. If a label is not defined, the device address will be
displayed. There is also a display format which will show the label comments
instead of the labels. Another display format shows the Mitsubishi addresses
assigned, and one more shows the IEC style address names.
These views can be changed from the View menu under ‘View Mode’. They can
also be cycled by using the Ctrl-Shift-M keyboard shortcut.
Numerous settings exist in the software options which will
affect the way the editor works. These can be customized to
personal preference, and settings are stored in the PC with
the software, not in the projects.
These settings can be found in the Tools menu under
‘Options. The tree to the right shows all of the pages related
to program editor operation. There are 3 pages related to the
structured ladder editor. Some of the settings deal with text
wrapping, default sizes, and label connectors for function
blocks.
Notes
LESSON 12 – Structured Ladder
Page 154
12.3 Editing Modes
There are 3 basic editor modes in the structured ladder editor. These modes
are:
•
•
•
Select mode, where the objects on the screen can be selected and moved
Interconnect mode, which is used to draw the connecting lines between
the contacts and coils
Guided mode, which is similar to the old GX Developer ladder editor
In select or interconnect mode, there is a setting for auto-connect. This autoconnect setting is used to make connecting lines to the connection points on the
symbols easier.
Each mode is indicated by the style of cursor displayed.
The structured ladder toolbar is shown below. The first 3 symbols are to select
the various modes. This toolbar also contains the ladder symbols, editing tools,
and zoom in and zoom out buttons.
Notes
LESSON 12 – Structured Ladder
Page 155
12.4 Ladder Symbols
The following table shows the ladder symbols which can be used in structured
ladder mode.
*1 AND/OR operation based on connections.
*2 GX Works2 version 1.15R or later.
Notes
LESSON 12 – Structured Ladder
Page 156
Ladder symbols can be created by keyboard shortcut keys or by clicking a button
on the toolbar and then the desired location in the ladder block. Pressing the
keyboard shortcut key will turn on the tool, and then the symbol will be drawn
where the mouse is clicked.
Notes
LESSON 12 – Structured Ladder
Page 157
Contacts and coils can have their function changed after drawing by double
clicking on the symbol. A dialog will appear offering the choices for the symbol.
12.5 Connecting Lines
When in the select mode with auto connect off, moving a ladder symbol or
function will move that object, but will not move the lines or variables which are
connected to it. Before moving the object, switch to auto connect mode so that
the lines will be moved with the object.
Without Auto-Connect
Notes
With Auto-Connect
LESSON 12 – Structured Ladder
Page 158
In select mode, the objects are not automatically connected with lines. The lines
will need to be added later in the interconnect mode.
In interconnect mode, the lines are connected to the symbols.
Click once on the power rail, and then move the mouse towards
where the other end of the line is to be connected. When the
black dot appears on the connection point, click again and the line will be drawn.
Branches can be added in this mode, as the black connector dots will appear
anywhere along the line of the rung above, as shown below.
When auto-connect mode is on, dragging will draw a line only between the click
and release points, and will draw around other symbols in the ladder block.
When auto-connect is off in interconnect mode, a line can be dragged directly
across a rung including multiple contacts, and each contact will be inserted into
the line.
Notes
LESSON 12 – Structured Ladder
Page 159
Sometimes is auto-connect mode lines are drawn which are not direct or straight.
There is a tool called ‘Recalculate Line’ which will align the lines. It can be found
in the Edit menu.
In guided mode, the screen is broken into a grid format. Symbols such as
contacts and coils will already have connecting lines as part of their grid. This is
more similar to the standard ladder editor and the GX Developer ladder editor.
This mode is useful when coding primarily from the keyboard.
Notes
LESSON 12 – Structured Ladder
Page 160
In guided mode, drawing a contact will result in the symbol as shown below.
Notice the horizontal line already connected to the edge of the block.
Another feature of guided mode is automatic comments on ladder blocks. This
can be enabled or disabled by a toolbar button or from the Guided Mode section
of the Edit menu. When this is enabled, a comment box is automatically created
across the top of each new ladder block inserted into the program.
12.6 Functions and Function Blocks
The simplest way to use functions or function blocks in the structured ladder
editor is to select the command from the selection window and drag it into the
program.
Function blocks will require inputs and output attached for connection of
variables. There is a setting in the software options which will insert these
automatically when the function is dropped into the structured ladder diagram.
This option is called ‘Automatic Input/Output Labels’. This setting only works
when in the auto-connect mode.
If the labels were not inserted automatically, there is a tool in the toolbar used to
add these labels manually. Addresses or labels used for numeric inputs and
outputs must be entered into these variables. Another setting in software options
allows the connector lines to remove the variable automatically, for example
when connecting a contact instead of a label.
Notes
LESSON 12 – Structured Ladder
Page 161
As previously mentioned, function blocks will require an instance name be
defined. This instance name is displayed directly above the function block.
Some functions and function blocks allow the number of inputs to be changed.
An example of this function is the OR_E instruction. This is an OR condition.
The _E on the end of the name indicates the function has an enable input, which
must be turned on for the command to execute. Another example of resizable
functions is the add (ADD_E) and subtract (SUB_E) instructions.
To add input pins onto the block, once it is selected, use the toolbar buttons to
add or remove pins. Pins can also be added and removed from the Edit menu
under Number of Pins. Another method is to click and drag the bottom edge of
the function until the desired number of pins is shown.
Another tool for inserting function blocks can be found in the toolbar. It is called
‘Input Instruction’. This pop-up dialog lets you type a command name (or part of
command name with lookup) and then enter the required parameters as was
previously done in GX Developer.
There is a ‘Browse Manual’ button at the right, which will display the instruction
help for the selected instruction from the programming manual.
Notes
LESSON 12 – Structured Ladder
Page 162
Once the command name is selected and a space is pressed, help will appear
indicating what format the data has to be in for each parameter.
Once the OK button or Enter is pressed, the mouse pointer will show a symbol of
a function block. Click in the ladder block to draw the instruction as configured.
As mentioned at the beginning of the lesson, structured ladder offers the entire
standard Mitsubishi command set, as well as new instructions from the standard
IEC libraries.
When referencing the Structured Programming manuals, several new data types
will be shown. The most commonly used ones are indicated below.
•
•
•
•
ANY_BIT means any type of bit address
ANY_NUM means any numeric values (word, double, floating point)
ANY_SIMPLE means any simple data type (no structures)
ANY includes arrays and structures
An example of a command which uses the new data types is ADD. Add uses
data type ANY_NUM. So this one command can be used to add 16-bit words,
32-bit words, as well as single or double precision floating point numbers. All
inputs to one function must be of the same data type.
So the same ADD instruction can be used in place of +, E+, D+, or ED+
instructions.
A table in Appendix 1 of the MELSEC-Q/L/F Structured Programming Manual
(Fundamentals) shows the memory areas usable for each data type.
Notes
LESSON 12 – Structured Ladder
Page 163
12.7 Constants
The method for specifying constants to a structured program is different than in
basic ladder. The table below shows the different methods which may be used
to enter a constant value into a function or function block.
Floating point data constants must have a decimal place in them. Some
instruction types will require a specific type of data. Be sure to use the
expression methods above to ensure the program compiles properly.
Notes
LESSON 12 – Structured Ladder
Page 164
12.8 Program Documentation
Comments can be placed anywhere within a ladder block. To insert a comment,
select the comment tool on the toolbar and then click in the ladder block. A
yellow box will be placed at the location of the mouse click.
Text can be entered by clicking once in the comment
window body and typing. It can be resized by clicking
and dragging the corners. It can be moved by clicking
and dragging on the header on the left side of the
comment box.
Multiple comment boxes can be placed in a single ladder
block. Comment blocks are not allowed to overlap each
other or any symbols in the ladder block.
There is an option setting in guided mode to automatically add a comment across
the top of each ladder block. When this option is selected, a comment box which
is one line of text high is created across the top of a number of cells in a new
ladder block. The number of cells can be defined in software options. This
would most closely resemble the statements used to comment rungs in simple
ladder.
Notes
LESSON 12 – Structured Ladder
Page 165
12.9 Monitoring
Monitoring can be stopped and started individually in any open window. Once
monitoring is started in a structured ladder window, the status of the devices is
shown as indicated below.
Contacts and coils will fill with a solid blue box when the contact or coil is true.
Bit devices used in functions and function blocks will highlight with blue boxes
around the address or label. If the bit is true, the box will be filled with dark blue.
If the bit is false, the box will be clear.
Numeric labels and addresses will display their value next to the label or address.
The format of the displayed numeric data will be based automatically on the type
of data used in the instruction. By default, U\G addresses do not monitor due to
the increased communications on the CPU bus.
Notes
LESSON 12 – Structured Ladder
Page 166
12.10 EXERCISE – Structured Ladder
Create a new structured project. Using the concepts explained in this lesson,
create the following program in the structured ladder language.
Write the program for a carton filling machine. The machine operator will enter a
number via the operator interface which indicates the number of products to
place in a carton. Once the start button is pressed, the conveyor will turn on to
move products into the carton. Products are counted by the product sensor.
When the number of products in the carton equals the number entered via the
operator interface, the conveyor will turn off. Turn on the indicator lamp when the
carton is filled. Turn it off when the system starts again.
DO NOT ALLOW THE CARTON SIZE TO BE CHANGED WHILE THE SYSTEM
IS RUNNING!
DO NOT USE A COUNTER FOR THIS EXERCISE.
Use the following addresses (to ensure the GOT program communicates
properly). Any addresses not listed below can be assigned anywhere in the PLC
memory, including labels without address definitions.
•
•
Notes
Bits
o Start
o Part Sensor
o Conveyor
o Carton Full Lamp
Words
o Carton Fill Size
o Current Number in Carton
M0
M1
Y0
Y1
D0
D1
LESSON 12 – Structured Ladder
Page 167
12.11 Timers and Counters
Timers and counters are not coded the same way in the structured ladder
program which they are coded in the standard ladder logic. Timers and counters
are coded as functions. The commands most comparable to the standard timer
and counter coils in ladder logic are:
•
•
•
OUT_T for a timer
OUTH_T for a high speed timer
OUT_C for a counter
Timers and counters also have a different method of distinguishing the timer
contact than in standard ladder. Each timer or counter has 3 addresses, as
indicated below.
•
•
•
TC is the timer coil, used on the OUT_T or OUTH_T function
TS is the completion indicator, used when coding a contact on the timer
TN (or just T) is the current value, used in word commands
•
STC, STS, and STN or ST are used for retentive timers
•
•
•
CC is the counter coil, used on the OUT_C function
CS is the completion indicator for use on contacts
CN (or just C) is the current value, used in word commands
These commands are covered in the Q/L Structured Programming Manual
(Common Instructions).
Notes
LESSON 12 – Structured Ladder
Page 168
An example of the OUT_T command is shown below.
The EN (enable) input starts the timer timing. The timer number is specified at
the TCoil input. The preset is specified at the TValue input. This is a word value,
and can be an integer or a variable name or a direct address.
Retentive timers use the same commands, but specify a retentive address in the
function’s input connections.
The OUT_C instruction is shown below.
Notes
LESSON 12 – Structured Ladder
Page 169
The IEC command set also includes standard timer and counter function blocks,
which are listed below.
•
•
•
•
•
•
TON for an on-delay timer
TOF for an off-delay timer
TP for a pulse timer
CTU for an up counter
CTD for a down counter
CTUD for an up/down counter
Adding an _E to the function block names above creates a function block with
enable input and enable output. These timer instructions take a preset value in
the time format standard, and output their current value in the time format.
These commands are covered in the Q/L Structured Programming Manual
(Application Instructions).
An example of the TON instruction is shown below. While Timer_Run is on, the
timer will time to a preset of 30 seconds, and then turn on output Y10. The
current elapsed time is stored in TON_Elapsed. The timer will reset
automatically when Timer_Run is turned off.
A retentive timer function can be accomplished with the TON_E command. The
EN input will allow the timer to time forward as long as IN is also true. When EN
turns off and IN remains on, the value in the timer is retained. When EN turns
back on, the timer will continue from its previous value. To reset the timer, EN
must be on while IN turns off.
Notes
LESSON 12 – Structured Ladder
Page 170
An example of the TON_E instruction is shown below. While Timer_Reset is off
and Timer_Run is on, the timer runs to a preset of 30 seconds, and then Y11
turns on. TONE_Elapsed will display the current elapsed time. In order to reset
the timer, EN must be on while IN is off, so Timer_Reset is used on both EN and
IN connections.
The example below is the CTU instruction. When g_bool1 turns on, count value
in g_int2 increments by one, and when g_bool2 turns on, count value is reset to 0.
Counter will count until the preset set in g_int1, and then output g_bool3 turns on.
The CTUD instruction can count up and down. Input CU causes a count up.
Input CD causes a count down. Inputs RESET and LOAD are the reset signals.
RESET will reset the counter to zero. LOAD will load the preset value into the
counter. The PV input is a number or register which stores the counter preset.
Output QU indicates when the counter has counted up to the preset value.
Output QD indicates when the counter has counted down to zero. Output CV
stores the current value of the counter.
Notes
LESSON 12 – Structured Ladder
Page 171
12.12 EXERCISE – Timers and Counters
This exercise will demonstrate the use of the timer and counter instructions in the
structured ladder language. Create a new structured project for this exercise.
PART 1
Write a program to control lead/lag status of 2 pumps. Each time a request for
water reaches the PLC, the lead pump should turn on. If that request is not
turned back off within 10 seconds, the second pump should turn on. When the
request turns off, all pumps should stop.
The pumps should alternate after each request to balance the run time on the
two pumps.
PART 2
Track total usage (in seconds) of each pump in data registers. Provide a switch
for each total to allow it to be reset.
Use the following addresses (to ensure the GOT program communicates
properly). Any addresses not listed below can be assigned anywhere in the PLC
memory, including labels without address definitions.
•
Bits
o
o
o
o
o
Water Request
P1 Hours Reset
P2 Hours Reset
Pump 1
Pump 2
M0
M15
M16
Y0
Y1
The word addresses used for the hours counting can be assigned anywhere, or
left unallocated. Monitor these values in the software.
Notes
LESSON 12 – Structured Ladder
Notes
Page 172
LESSON 13 – Structured Text
Page 173
LESSON 13 – Structured Text
This lesson will introduce the structured text programming language.
Lesson Objectives
At the conclusion of this lesson, you will be able to…
• Explain the syntax of the structured text programming language.
• Write programs in structured text.
13.1 Introduction
The structured text language is a text-based programming language similar in
syntax to the C programming language on a PC. Grammatical layout and
command names are very similar to C programming. By using the structured text
language, a person familiar with PC programming can easily write code for a
PLC.
Structured text can be used for complex programming applications, such as
conditional judgment, mathematical formulas, and repeating processes, which
may not be easily written in the structured ladder language.
By using simple assignment syntax, mathematical formulas can be calculated
without creating a series of ladder functions as previously used. As an example,
Celsius to Fahrenheit conversion would typically be accomplished by multiplying
the incoming Celsius number by 9, dividing that result by 5, and then adding 32
to that result. This is 3 separate math commands in ladder logic, as shown
below.
In structured text, it can be written as shown below.
Deg_F := (9 * Deg_C) / 5 +32;
Notes
LESSON 13 – Structured Text
Page 174
13.2 Editor Basics
Lines of code in structured text are called syntaxes. Each syntax must end with
a semicolon. Functions and function blocks can be called from within a
structured text program as shown below.
Spaces, tabs, and line breaks can be inserted anywhere between keywords and
identifiers. The examples shown below are called assignment syntaxes. Each is
assigning a numeric value to a variable. Both examples are valid code, and
perform the same function.
Comments can be entered at any location in the program by enclosing the
comment text as shown below.
Notes
LESSON 13 – Structured Text
Page 175
GX Works2 will automatically apply color codes to the text in a structured text
program to make the program easier to read. The color codes are adjustable in
the software options. The default settings are shown below.
GX Works2 will also automatically tab indent consecutive lines of the same
command, as demonstrated above. Lines are indented until the semicolon
indicates the end of that syntax.
GX Works2 will perform automatic completion of the label names used while
programming. When entering a label, all labels beginning with the typed
characters are displayed and can be selected from the selection list. If only one
label matches, it will be automatically filled in. The auto-complete function uses
both the global label list and the local labels of the edited program. The project
should be saved with the labels entered for this function to work.
Labels can be added while editing program by pressing F2 or using List
Operands from the Edit menu.
Notes
LESSON 13 – Structured Text
Page 176
The structured text editor has a bookmark tool for quick navigation of a program.
The programmer can set bookmarks on various lines in the program, and use
keyboard shortcuts or a list window to navigate the bookmarks.
The bookmark tools are found at the bottom of the Find/Replace menu.
They are also available from the structured text toolbar.
Bookmarks are registered with Ctrl-F7, or the tool in the toolbar, and apply to the
line in the structured text. Clicking the tool or pressing Ctrl-F7 again on the same
rung will remove the bookmark.
Bookmarks are shown in the software as a light blue box in the gray
margin on the left hand side of the structured text program.
There is a list window for browsing all of the bookmarks set in the
program. From this window the programmer can jump to any
bookmark, or can clear all bookmarks.
Notes
LESSON 13 – Structured Text
Page 177
13.3 Operators
The table below shows the available operators in the ST language and their
execution priority. This priority sets the order of execution of the operators within
a single syntax.
If multiple operators in a syntax have the same priority, they are processed left to
right.
13.4 Syntaxes
There are 4 basic syntax types in structured text.
•
•
•
•
Notes
Assignment syntax
Conditional syntax
Iteration syntax
Control syntax
LESSON 13 – Structured Text
Page 178
Assignment syntax is used to assign a value to a label or address. The labels or
addresses must represent the same data format, such as an integer or real
number. Assignment syntax uses a colon followed by an equal sign, as shown
below.
Conditional syntaxes are used to perform an action when a Boolean expression
is true. Samples of conditional syntax include IF THEN, IF ELSE, IF ELSIF and
CASE. The result of the IF is always a Boolean TRUE/FALSE condition. Some
examples of conditional syntax are shown below. Conditional syntaxes can be
nested to 16 levels.
The IF instruction will run the included statements only
if the expression is true. If it is false, nothing is
executed.
The IF ELSE instruction will run one of two
sets of statements, depending on whether
the condition is true or false.
Notes
LESSON 13 – Structured Text
Page 179
The IF ELSIF command will process one of several sets of statements depending
on the status of multiple comparisons. If the first expression is false, the ELSIF
instruction is performed. If that expression is false, the next ELSIF is performed.
If none of the conditions is true, nothing is performed.
Notes
LESSON 13 – Structured Text
Page 180
The CASE instruction is considered a conditional syntax, and the result is based
on which case in the instruction is true. The value evaluated by the case
instruction is an integer value. If none of the cases are true, the ELSE condition
is executed, if present. Cases can be established based on a single value,
multiple values separated by commas, or a range of numbers defined by a
double period in between the lower and upper values. Multiple formats can be
combined within a single case. If more than one case applies, the first one which
applies is executed, and the other cases are not executed.
Iteration syntaxes are used to repeat an assignment or function. The FOR DO
syntax repeats a command a specified number of times. The WHILE DO syntax
repeats as long as the Boolean condition is true. The REPEAT UNTIL syntax
continues to repeat until a boolean condition becomes true.
Notes
LESSON 13 – Structured Text
The FOR loop will repeat a specified number
of times, and can increment a value at each
execution. The FOR value is assigned a
starting value. The BY portion sets up the
amount to increment the value, and is
optional. The DO portion of the command
sets the actions to repeat.
The WHILE command will continue to repeat
as long as the condition expression is true.
Once the condition is false, execution will
pass from the loop to the next instructions.
Notes
Page 181
LESSON 13 – Structured Text
Page 182
The REPEAT UNTIL command will continue to run as
long as the condition set by UNTIL is true.
The control syntaxes are used to modify the execution of a program. The
RETURN instruction will jump to the end of the structured text program, ignoring
the remaining program steps. The EXIT instruction is used to break out of an
iteration syntax before the end of its process.
Notes
LESSON 13 – Structured Text
Page 183
13.5 Functions and Function Blocks
When coding a function in structured text, the variables for the function are
enclosed in parentheses after the name of the function. If there is more than one
variable required, they are separated by commas.
The result of the function is stored to the variable as designated by the
assignment syntax. The examples below show functions with one variable and
three variables.
Function blocks can require more than one input, and can have more than one
output. The function block must have an instance declared, so be sure to add a
local variable of the data type to match the desired command.
The function block is called by its instance name, and then both the inputs and
outputs can be defined inside parentheses. The name of the signal and the
value must be specified with an assignment syntax.
Inputs and outputs can also be defined using assignment syntax. The inputs will
be defined prior to the function block call, and the outputs will be defined after the
function block is called.
Notes
LESSON 13 – Structured Text
Page 184
The example below shows a function block with one input and one output, with
the output shown in a separate assignment syntax. Notice the name of the
function block is not used in the command, only the name of the instance. An
example of what this function block would look like in structured ladder is
provided only as a reference, as it would not be coded in the program.
Variables are assigned with the typical assignment syntax inside the parentheses
by assigning the input or output name to the variable. In the example below,
outputs are handled outside the function block in an assignment syntax.
Another method of writing this code, with input and output parameters included in
the one syntax, is shown below.
The third method to write this function block is using assignment syntax for all
inputs and outputs.
Notes
LESSON 13 – Structured Text
Below is an example of a function block with 3 inputs and two outputs.
The three different ways to call this instruction are shown below.
Notes
Page 185
LESSON 13 – Structured Text
Page 186
13.6 Monitoring
Monitoring can be started on a structured text program. When monitoring is
started, the structured text program window is split into 2 columns. On the left
side will be the structured text code, and on the right side will be a list of the
numeric variables used in the program.
Bits can be monitored on the left side of the screen. Boxes around the bit labels
or addresses will display the on or off status of that variable. If the box is white,
the contact is not true. If the box is solid, the contact is on.
Numeric values can be monitored in the right half of the window. All numeric
variables in the program will be displayed in the right window automatically, and
the value will be listed next to the variable name or address. Values are
displayed next to each line where the label was used in the structured text
program, so many labels may be listed more than once in the right window.
The picture below demonstrates monitoring in a structured text program.
Notes
LESSON 13 – Structured Text
Page 187
13.7 EXERCISE – Structured Text
Write a structured text program to perform the following tasks.
Create a new structured project for this exercise.
1. Write a data table storing a number from D0 on the operator interface
each time the trigger (M0) is pressed. Use the FIFW command to build
this table, and start the table at D100.
2. Only allow this table to store 10 samples. When 10 samples exist and the
data store trigger is pressed, use the FIFR command to remove the oldest
entry in the table before storing the new value.
3. Enable the operator to reset all of the data in the table with the reset
button (M1) by writing an FMOV instruction.
4. Calculate the average of all of the entries in the table. The MEAN
instruction can be used to calculate the average. Store the result of this
calculation in D120.
5. Search the minimum value in the table, using the MIN instruction, and
store it to D122.
6. Search the maximum value in the table, using the MAX instruction, and
store it to D125.
Notes
LESSON 13 – Structured Text
Page 188
13.8 Inline Structured Text Box
It is possible with GX Works2 to place a block of structured text code at the
output end of a rung of simple ladder, in either simple or structured projects. This
function is convenient for embedding small amounts of structured text in the
ladder program, such as mathematical functions or character string processing.
In order to use this function, a setting must be made in the software options. In
the Compile section, under Basic Setting, be sure that the ‘Enable function block
call from ladder to ST and from ST to ladder’ option is checked. This option is
checked by default.
The inline structured text block is an output, so it justifies to the right side of the
ladder window. It must have a contact in front of it in order to be a valid rung of
code. There cannot be more than one structured text block per rung, and no
vertical lines can be drawn in front of the inline structured text box.
Select the Edit menu, then Inline Structured Text, then Insert Inline Structured
Text Box to insert an ST block into the ladder. It can also be accomplished from
the keyboard by pressing Ctrl-B, or by typing STB in the enter symbol dialog
without choosing a ladder symbol.
Programs can be edited in the structured text box by double clicking on the box.
Editing programs in the structured text box is done the same as editing a
structured text program.
When finished editing the inline structured text box, click any area outside the
box, or press the ESC key. This will end the editing of the block.
Notes
LESSON 13 – Structured Text
Page 189
To see the results of the compile of an inline structured text block, select ‘Display
Compile Result’ from the View menu. This will show the instruction list code
generated to perform the actions in the structured text box.
As an example, here is the structured text to average 4 values.
Here is the result of the compile in instruction list.
There are some basic precautions when working with the inline structured text
box. They are shown below.
•
•
•
•
•
•
•
Notes
One box can be created per ladder rung
Function blocks and inline ST boxes cannot be used in the same ladder
rung
Ladder cannot be edited while uncompiled ST boxes exist
Up to 2048 characters can be entered into an inline ST box
Counters, timers, pointers, structures, arrays, and function blocks cannot
be used in the inline ST box
To delete an inline ST box, select the entire rung, including the left base
line
Up to 100 structured text boxes can be inserted into a program, with a
maximum of 400 per project for Q Series or L Series
LESSON 13 – Structured Text
Page 190
13.9 EXERCISE – Inline Structured Text Box
Add a simple ladder program to the project from the previous exercise.
In this program, perform conversion from Celsius to Fahrenheit on a value stored
via the operator interface screen. The formula was discussed at the beginning of
this lesson.
To verify proper operation, test with the following values:
°C =
°F
°C =
°F
To ensure the operator interface communication, use the following addresses.
•
•
Notes
Celsius temperature input to D200
Fahrenheit temperature to be stored to D210
APPENDIX
Page 191
APPENDIX
Notes
APPENDIX
Notes
Page 192
APPENDIX
Page 193
APPENDIX 1 – L Series USB Driver Installation
The following steps must be followed to install the L Series USB driver. The files
required are copied to the hard drive during the installation of GX Works2, so no
CDs or diskettes are required.
When the cable is first connected, Windows will show the ‘Found New Hardware’
wizard. The following screen will be displayed.
Select the ‘No, not this time’ option and click Next.
Notes
APPENDIX
Page 194
The next screen asks how to find the driver to be installed.
Choose ‘Install from a list or specific location (Advanced) and click Next.
Notes
APPENDIX
Page 195
The next screen will ask for the location of the driver to install.
Ensure the ‘Include this location in the search’ box is checked, and click Browse.
Find the directory C:\Program Files\MELSEC\EasySocket\USBDrivers and
click OK. This will return you to the screen shown above. Click Next to move on.
Notes
APPENDIX
Page 196
The next window will state that this driver has not passed Windows XP Logo
testing.
Click ‘Continue Anyway’ to proceed with the installation.
Notes
APPENDIX
The final screen indicates successful installation of the USB drivers.
Notes
Page 197
APPENDIX
Page 198
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