Mitsubishi Electric MELSEC Q Series Owner's manual

MELSEC-Q/L
Programming Manual (MELSAP-L)

1
SAFETY PRECAUTIONS
Before using MELSEC-Q or -L series programmable controllers, please read the manuals included with each product and the
relevant manuals introduced in those manuals carefully, and pay full attention to safety to handle the product correctly.
Make sure that the end users read the manuals included with each product, and keep the manuals in a safe place for future
reference.
CONDITIONS OF USE FOR THE PRODUCT
INTRODUCTION
Thank you for purchasing the Mitsubishi Electric MELSEC-Q/L series programmable controllers.
Before using the product, please read this manual carefully and develop familiarity with the functions and performance of the
MELSEC-Q/L series programmable controllers to handle the product correctly.
When applying the program examples provided in this manual to an actual system, ensure the applicability and confirm that it
will not cause system control problems.
Please make sure that the end users read this manual.
(1) Mitsubishi programmable controller ("the PRODUCT") shall be used in conditions;
i) where any problem, fault or failure occurring in the PRODUCT, if any, shall not lead to any major or serious accident;
and
ii) where the backup and fail-safe function are systematically or automatically provided outside of the PRODUCT for the
case of any problem, fault or failure occurring in the PRODUCT.
(2) The PRODUCT has been designed and manufactured for the purpose of being used in general industries.
MITSUBISHI SHALL HAVE NO RESPONSIBILITY OR LIABILITY (INCLUDING, BUT NOT LIMITED TO ANY AND ALL
RESPONSIBILITY OR LIABILITY BASED ON CONTRACT, WARRANTY, TORT, PRODUCT LIABILITY) FOR ANY
INJURY OR DEATH TO PERSONS OR LOSS OR DAMAGE TO PROPERTY CAUSED BY the PRODUCT THAT ARE
OPERATED OR USED IN APPLICATION NOT INTENDED OR EXCLUDED BY INSTRUCTIONS, PRECAUTIONS, OR
WARNING CONTAINED IN MITSUBISHI'S USER, INSTRUCTION AND/OR SAFETY MANUALS, TECHNICAL
BULLETINS AND GUIDELINES FOR the PRODUCT.
("Prohibited Application")
Prohibited Applications include, but not limited to, the use of the PRODUCT in;
• Nuclear Power Plants and any other power plants operated by Power companies, and/or any other cases in which the
public could be affected if any problem or fault occurs in the PRODUCT.
• Railway companies or Public service purposes, and/or any other cases in which establishment of a special quality
assurance system is required by the Purchaser or End User.
• Aircraft or Aerospace, Medical applications, Train equipment, transport equipment such as Elevator and Escalator,
Incineration and Fuel devices, Vehicles, Manned transportation, Equipment for Recreation and Amusement, and
Safety devices, handling of Nuclear or Hazardous Materials or Chemicals, Mining and Drilling, and/or other
applications where there is a significant risk of injury to the public or property.
Notwithstanding the above, restrictions Mitsubishi may in its sole discretion, authorize use of the PRODUCT in one or
more of the Prohibited Applications, provided that the usage of the PRODUCT is limited only for the specific
applications agreed to by Mitsubishi and provided further that no special quality assurance or fail-safe, redundant or
other safety features which exceed the general specifications of the PRODUCTs are required. For details, please
contact the Mitsubishi representative in your region.

2
CONTENTS
SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
CONDITIONS OF USE FOR THE PRODUCT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
RELEVANT MANUALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
CHAPTER 1 GENERAL DESCRIPTION 7
1.1 Description of SFC Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2 SFC (MELSAP-L) Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
CHAPTER 2 SYSTEM CONFIGURATION 17
2.1 Applicable CPU Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2 Peripheral Devices for SFC Programs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
CHAPTER 3 SPECIFICATIONS 19
3.1 Performance Specifications Related to SFC Programs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2 Device List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.3 Processing Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Processing time for SFC program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Processing time for S(P).SFCSCOMR instruction and S(P).SFCTCOMR instruction. . . . . . . . . . . . . . . . . . . . . 34
3.4 Calculating the SFC Program Capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Method for calculating the SFC program capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Number of steps required for expressing the SFC diagram as SFC dedicated instructions . . . . . . . . . . . . . . . . 37
CHAPTER 4 SFC PROGRAM CONFIGURATION 38
4.1 List of SFC Diagram Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.2 Steps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Step (without step attribute). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Initial step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Dummy step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Coil HOLD step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Operation HOLD step (without transition check) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Operation HOLD step (with transition check) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Reset step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Block START step (with END check). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Block START step (without END check) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
End step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Instructions that cannot be used with operation outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.3 Transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Serial transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Selection transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Parallel transition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Jump transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Precautions for creating operation output (step)/transition condition programs . . . . . . . . . . . . . . . . . . . . . . . . .68
4.4 Controlling SFC Programs by Instructions (SFC Control Instructions). . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Step operation status check instructions (a, b, &a, &b, |a, |b) [Sn/BLm\Sn] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Forced transition check instruction (a, b, &a, &b, |a, |b) [TRn/BLm\TRn] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Block operation status check instruction (a, b, &a, &b, |a, |b) [BLm]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3
CONTENTS
Active step batch readout (MOV and DMOV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Active step batch readout (BMOV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Block START & END instructions (s, r) [BLm] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Block STOP and RESTART instructions (PAUSE, RSTART) [BLm]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92
Step START and END instructions (s, r) [Sn/BLm\Sn] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Forced transition EXECUTE & CANCEL instructions (s, r) [TRn/BLm\TRn] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Active step change instruction (SCHG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Block switching instruction (BRSET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
4.5 SFC Information Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Block START/END bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Step transition bit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Block STOP/RESTART bit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Block STOP mode bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Continuous transition bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Number of active steps register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
4.6 Step Transition Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
4.7 SFC Operation Mode Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
SFC program start mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Block 0 START condition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Output mode at block STOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Periodic execution block setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Operation mode at double block START . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Operation mode at transition to active step (double step START) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
4.8 SFC Comment Readout Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
SFC comment readout instruction (S(P). SFCSCOMR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
SFC transition comment readout instruction (S(P). SFCTCOMR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
CHAPTER 5 SFC PROGRAM PROCESSING SEQUENCE 145
5.1 Whole Program Processing of Basic Model QCPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Whole program processing sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
5.2 Whole Program Processing of High Performance Model QCPU, Process CPU, Redundant CPU,
Universal Model QCPU, and LCPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Whole program processing sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Execution type designation by instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
SFC program for program execution management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
5.3 SFC Program Processing Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
SFC program execution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Block execution sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
Step execution sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Continuous transition ON/OFF operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
CHAPTER 6 SFC PROGRAM EXECUTION 158
6.1 SFC Program START and STOP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
SFC program resumptive START procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
6.2 Block START and END . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Block START methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Block END methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
6.3 Block Temporary Stop and Restart Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Block STOP methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Restarting a stopped block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

4
6.4 Step START (Activate) and END (Deactivate) Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Step START (activate) methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Step END (deactivate) methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Changing an active step status (Not available for Basic model QCPU, Universal model QCPU,
and LCPU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
6.5 Operation Methods for Continuous Transition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
6.6 Operation at Program Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Operation at program change made by write to PLC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Program change by online change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Online change (inactive block) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
APPENDICES 174
Appendix 1 Special Relay and Special Register List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Special Relay (SM) List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Special Register (SD) List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Appendix 2 Restrictions on Basic Model QCPU, Universal Model QCPU, and LCPU
and Alternative Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Step Transition Watchdog Timer Replacement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Periodic Execution Block Replacement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Forced Transition Bit (TRn) Replacement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Active Step Change Instruction (SCHG) Replacement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
INDEX 186
INSTRUCTION INDEX 188
REVISIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .190
WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191
TRADEMARKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .192

5
RELEVANT MANUALS
e-Manual refers to the Mitsubishi Electric FA electronic book manuals that can be browsed using a dedicated
tool.
e-Manual has the following features:
• Required information can be cross-searched in multiple manuals.
• Other manuals can be accessed from the links in the manual.
• The hardware specifications of each part can be found from the product figures.
• Pages that users often browse can be bookmarked.
Manual name [manual number] Description Available form
GX Developer Version 8 Operating Manual (MELSAP-L)
[SH-080375E]
Describes how to create SFC programs using the software package for
creating SFC programs.
Print book
PDF
GX Works2 Version1 Operating Manual (Common)
[SH-080779ENG]
Describes system configurations, parameter settings, online operations
(common to Simple project and Structured project) of GX Works2.
Print book
PDF
QnUCPU User's Manual (Function Explanation, Program
Fundamentals)
[SH-080807ENG]
Describes the functions required for programming, programming
methods, and devices.
Print book
PDF
Qn(H)/QnPH/QnPRHCPU User's Manual(Function Explanation,
Program Fundamentals)
[SH-080808ENG]
Describes the functions required for programming, programming
methods, and devices.
Print book
PDF
MELSEC-L CPU Module User's Manual (Function Explanation,
Program Fundamentals)
[SH-080889ENG]
Describes the functions required for programming, programming
methods, and devices.
Print book
e-Manual
PDF
MELSEC-Q/L Programming Manual (Common instruction)
[SH-080809ENG]
Describes how to use sequence instructions, basic instructions, and
application instructions.
Print book
e-Manual
PDF

6
TERMS
Unless otherwise specified, this manual uses the following generic terms and abbreviations.
Generic term Description
Basic A generic term for the Q00JCPU, Q00CPU, and Q01CPU
Basic model QCPU
High Performance A generic term for the Q02CPU, Q02HCPU, Q06HCPU, Q12HCPU, and Q25HCPU
High Performance model QCPU
High-speed Universal model
QCPU
A generic term for the Q03UDVCPU, Q04UDVCPU, Q06UDVCPU, Q13UDVCPU, and Q26UDVCPU
LCPU A generic term for the L02SCPU, L02SCPU-P, L02CPU, L02CPU-P, L06CPU, L06CPU-P, L26CPU, L26CPU-P, L26CPU-
BT, and L26CPU-PBT
Process CPU A generic term for the Q02PHCPU, Q06PHCPU, Q12PHCPU, and Q25PHCPU
Programming tool A generic term for GX Developer and GX Works2
QCPU A generic term for the Basic model QCPU, High Performance model QCPU, Process CPU, Redundant CPU, and
Universal model QCPU
QnCPU A generic term for the Q02CPU
QnHCPU A generic term for the Q02HCPU, Q06HCPU, Q12HCPU, and Q25HCPU
QnPHCPU A generic term for the Q02PHCPU, Q06PHCPU, Q12PHCPU, and Q25PHCPU
QnPRHCPU A generic term for the Q12PRHCPU and Q25PRHCPU
Redundant CPU A generic term for the Q12PRHCPU and Q25PRHCPU
Universal A generic term for the Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCPU, Q03UDCPU, Q03UDVCPU, Q03UDECPU,
Q04UDHCPU, Q04UDVCPU, Q04UDEHCPU, Q06UDHCPU, Q06UDVCPU, Q06UDEHCPU, Q10UDHCPU,
Q10UDEHCPU, Q13UDHCPU, Q13UDVCPU, Q13UDEHCPU, Q20UDHCPU, Q20UDEHCPU, Q26UDHCPU,
Q26UDVCPU, Q26UDEHCPU, Q50UDEHCPU, and Q100UDEHCPU
Universal model QCPU

1 GENERAL DESCRIPTION
7
1
1GENERAL DESCRIPTION
SFC, an abbreviation for "Sequential Function Chart", is a control specification description format in which a sequence of
control operations is split into a series of steps to enable a clear expression of the program execution sequence and execution
conditions.
This manual describes the specifications, functions, instructions, programming procedures, etc. used to perform programming
with an SFC program using MELSAP-L.
MELSAP-L can be used with the following CPU modules.
MELSAP-L conforms to the IEC Standard for SFC.
• Basic model QCPU whose serial number (first five digits) is 04122 or later
• High Performance model QCPU
• Process CPU
• Redundant CPU
• Universal model QCPU
•LCPU
In this manual, MELSAP-L is referred to as SFC (program, diagram).
• The following functions cannot be executed if a parameter that sets the "high speed interrupt cyclic interval"
is loaded into a High Performance model QCPU of which the first 5 digits of the serial number are "04012"
or later.
Page 117 Step Transition Watchdog Timer
Page 119 SFC Operation Mode Setting
• The QCPU-A (A mode) cannot use MELSAP-L explained in this manual.

81 GENERAL DESCRIPTION
When created with MELSAP-L and ladders
Description format with MELSAP-L
MELSAP-L side Sequence programs side
The flow of operation is easy to understand by creating the SFC program
related to the interlock conditions.
The area can be developed into a product by creating interlock conditions
irrelevant to the flow of operation.

1 GENERAL DESCRIPTION
1.1 Description of SFC Program 9
1
1.1 Description of SFC Program
The SFC program consists of steps that represent units of operations in a series of machine operations.
In each step, the actual detailed control is programmed by using a ladder circuit.
Grouping steps into one block in process units allows to create an SFC program that is capable of tracking all the processes
as well as structuring the operation flow in each process.
An SFC program starts at an initial step, executes a step following a transition condition in due order every time that transition
condition is satisfied, and ends a series of operations at an end step.
• When the SFC program is started, the "initial" step is executed first.
• Execution of the initial step continues until transition condition 0 is satisfied. When this transition condition is satisfied,
execution of the initial step is stopped, and processing proceeds to the step which follows the initial step.
Processing of the SFC program continues from step to step in this manner until the END step has been executed.

10 1 GENERAL DESCRIPTION
1.2 SFC (MELSAP-L) Features
1.2 SFC (MELSAP-L) Features
This section describes the SFC (MELSAP-L) features.
Easy to design and maintain systems
It is possible to correspond the controls of the entire facility, mechanical devices of each station, and all machines to the
blocks and steps of the SFC program on a one-to-one basis. Because of this capability, systems can be designed and
maintained with ease even by those with relatively little knowledge of sequence programs.
Moreover, programs designed by other programmers using this format are much easier to decode than sequence programs.

1 GENERAL DESCRIPTION
1.2 SFC (MELSAP-L) Features 11
1
Program development efficiency is enhanced by dividing control into parts
The machine control process can be divided into parts by describing the operation sequence and machine control separately.
The MELSAP-L is used to describe the operation sequence for the machine, and a sequence program (circuit/list) is used to
describe the machine control including individual interlock.

12 1 GENERAL DESCRIPTION
1.2 SFC (MELSAP-L) Features
Block and step configurations can easily be changed for new control applications
• A total of 320 blocks*1 can be created in an SFC program.
• Up to 512 steps*1 can be created per block.
• Up to 2K sequence steps of operation outputs/transition conditions can be created in all blocks.
Reduced tact times, as well as easier debugging and trial run operations are possible by dividing blocks and steps as follows:
• Divide blocks properly according to the operation units of machines.
• Divide steps in each block properly.
*1 For the following CPU modules, 128 blocks and 128 steps can be created.
Basic model QCPU
Universal model QCPU (Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCPU)
LCPU (L02SCPU, L02SCPU-P, L02CPU, L02CPU-P)

1 GENERAL DESCRIPTION
1.2 SFC (MELSAP-L) Features 13
1
Creation of multiple initial steps is possible
Multiple processes can easily be executed and combined. Initial steps are linked using a "selection coupling" format. When
multiple initial steps (S0 to S3) are active, the step where the transition condition (t4 to t7) immediately prior to the selected
coupling is satisfied becomes inactive, and a transition to the next step occurs.
Moreover, when the transition condition immediately prior to an active step is satisfied, the next step is executed in
accordance with the parameter settings.
Basic model QCPU, Universal model QCPU, and LCPU cannot be selected in the parameter setting. It
operates in the default "Transfer" mode.
• Wait: Transition to the next step occurs after waiting for the next step to become inactive.
• Transfer: Transition to the next step occurs even if the next step is active. (Default)
• Pause: An error occurs if the next step is active.
Linked steps can also be changed at each initial step.

14 1 GENERAL DESCRIPTION
1.2 SFC (MELSAP-L) Features
Program design is easy due to a wealth of step attributes
A variety of step attributes can be assigned to each step. Used singly for a given control operation, or in combination, these
attributes greatly simplify program design procedures.
■Types of HOLD steps, and their operations
• Coil HOLD step
• Operation HOLD step (no transition check)
• Operation HOLD step (with transition check)
• After transition, the operation of the operation output is continued (put in
HOLD status) and the coil output status when the transition condition is
satisfied is maintained.
• Transition will not occur if the transition condition is satisfied again.
• Convenient for maintaining an output until the corresponding block is
completed (hydraulic motor output, pass confirmation signal, etc.).
• When the output mode at block stop is OFF, it remains OFF after a block
restart.
• After transition, the operation of the operation output is continued (put in
HOLD status).
• Transition will not occur if the transition condition is satisfied again.
• When the output mode at block stop is OFF, the operation is continued after a
block restart, and therefore, the output is provided as a result of the operation
that has been performed.
• After transition, the operation of the operation output is continued (put in HOLD
status).
• When the transition condition is satisfied again, transition is executed and the
next step is reactivated.
• Operation output processing is executed at the reactivated next step. When the
transition condition is satisfied, transition occurs, and the step is deactivated.

1 GENERAL DESCRIPTION
1.2 SFC (MELSAP-L) Features 15
1
■Reset step
■Types of block START steps, and their operations
• Block START step (with END check)
• Block START step (Without END check)
When a HOLD status becomes unnecessary for machine control, or on selective
branching to a manual ladder occurs after an error detection, etc., a reset request
can be designated for the HOLD step, deactivating the step in question.
• In the same manner as for a subroutine CALL-RET, a START source block
transition will not occur until the end of the START destination block is reached.
• Convenient for starting the same block several times, or to use several blocks
together, etc.
• A convenient way to return to the START source block and proceed to the next
process block when a given process is completed in a processing line, for
example.
• Even if the START destination block is active, a START source block transition
occurs when the transition condition associated with the block START step is
satisfied. At this time, the processing of the START destination block will be
continued unchanged until the end step is reached.
• By starting another block at a given step, the START destination block can be
controlled independently and asynchronously with the START source block
until processing of the current block is completed.

16 1 GENERAL DESCRIPTION
1.2 SFC (MELSAP-L) Features
A given function can be controlled in a variety of ways according to the application
Block functions such as START, END, temporary stop, restart, and forced activation and ending of specified steps can be
controlled by SFC diagram symbols, SFC control instructions, or by SFC information registers.
Functions which can be controlled by multiple methods are shown below.
In cases where the same function can be executed by a number of methods, the first control method which has been
designated by the request output to the block or step in question will be the effective control method. Functions controlled by
a given control method can be canceled by another control method.
Ex.
For block START, the active block started by the SFC diagram can be forcibly ended by executing the SFC control instruction
before the END step or by turning OFF the block START/END bit of the SFC information devices.
Automatic scrolling function enables quick identification of machine system troubles
The execution of an active (execution) block, an active (execution) step, an operation output/transition condition can be
monitored (with the automatic scrolling function) from peripheral devices. Moreover, the transition watchdog function enables
the detection of the step where transition does not occur after the designated time elapses. These monitoring functions allow
you to track down the spot where a problem occurs without a broad knowledge about sequence programs.
Control method Description
Control by SFC diagram symbols Convenient for control of automatic operations with easy sequential control.
Control by SFC instructions Enables requests from program files other than the SFC, and is convenient for error processing, for example after
emergency stops, and interrupt control.
Control by SFC information devices Enables control of SFC peripheral devices, and is convenient for partial operations such as debugging or trial runs.
Function Control Method
SFC Diagram SFC Control Instructions SFC Information Registers
Block START (with END wait) Bm 
Block START (without END wait) Bm sBLm Block START/END bit ON
Block END rBLm Block START/END bit OFF
Block STOP PAUSE BLm Block PAUSE/RESTART bit ON
Restart stopped block RSTART BLm Block PAUSE/RESTART bit OFF
Forced step activation •sSn
• sBLm\Sn

Forced step END Sn •rSn
• rBLm\Sn


2 SYSTEM CONFIGURATION
2.1 Applicable CPU Modules 17
2
2SYSTEM CONFIGURATION
This chapter describes the system configuration of the SFC program.
2.1 Applicable CPU Modules
MELSAP-L (SFC programs) runs on the following CPU modules.
*1 Modules whose serial number (first five digits) is 04122 or later
CPU module type Model name
Basic model QCPU*1 Q00JCPU, Q00CPU, Q01CPU
High Performance model QCPU Q02CPU, Q02HCPU, Q06HCPU, Q12HCPU, Q25HCPU
Process CPU Q02PHCPU, Q06PHCPU, Q12PHCPU, Q25PHCPU
Redundant CPU Q12PRHCPU, Q25PRHCPU
Universal model QCPU Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCPU, Q03UDCPU, Q03UDVCPU, Q03UDECPU, Q04UDHCPU,
Q04UDEHCPU, Q04UDVCPU, Q06UDHCPU, Q06UDVCPU, Q06UDEHCPU, Q10UDHCPU, Q10UDEHCPU,
Q13UDHCPU, Q13UDVCPU, Q13UDEHCPU, Q20UDHCPU, Q20UDEHCPU, Q26UDHCPU, Q26UDVCPU,
Q26UDEHCPU, Q50UDEHCPU, Q100UDEHCPU
LCPU L02SCPU, L02SCPU-P, L02CPU, L02CPU-P, L06CPU, L06CPU-P, L26CPU, L26CPU-P, L26CPU-BT, L26CPU-PBT

18 2 SYSTEM CONFIGURATION
2.2 Peripheral Devices for SFC Programs
2.2 Peripheral Devices for SFC Programs
The following peripheral devices can be used to create, edit and monitor SFC programs. The numbers in the following table
mean (1): Basic model QCPU, (2): High Performance model QCPU, (3): Process CPU, (4): Redundant CPU, (5): Universal
model QCPU, and (6): LCPU.
: Available, : Not available, : Partly available
*1 Available only with the Q02UCPU, Q03UDCPU, Q04UDHCPU, and Q06UDHCPU
*2 Available only with the Q12PHCPU and Q25PHCPU
*3 Available only with the Q02UCPU, Q03UDCPU, Q04UDHCPU, Q06UDHCPU, Q13UDHCPU, and Q26UDHCPU
*4 Available only with the Q02UCPU, Q03UD(E)CPU, Q04UD(E)HCPU, Q06UD(E)HCPU, Q13UD(E)HCPU, and Q26UD(E)HCPU
*5 Available only with the Q00U(J)CPU, Q01UCPU, Q02UCPU, Q03UD(E)CPU, Q04UD(E)HCPU, Q06UD(E)HCPU, Q10UD(E)HCPU,
Q13UD(E)HCPU, Q20UD(E)HCPU, and Q26UD(E)HCPU
*6 Available only with the Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCPU, Q03UDCPU, Q03UDECPU, Q04UDHCPU, Q04UDEHCPU,
Q06UDHCPU, Q06UDEHCPU, Q10UDHCPU, Q10UDEHCPU, Q13UDHCPU, Q13UDEHCPU, Q20UDHCPU, Q20UDEHCPU,
Q26UDHCPU, Q26UDEHCPU, Q50UDEHCPU, and Q100UDEHCPU
*7 Available only with the L02CPU, L02CPU-P, L26CPU-BT, and L26CPU-PBT
*8 Available only with the L02SCPU, L02CPU, L02CPU-P, L26CPU, L26CPU-BT, and L26CPU-PBT
*9 Available only with the L02CPU and L26CPU-BT
Peripheral device Software package to be installed in a personal
computer
CPU module
(1) (2) (3) (4) (5) (6)
Personal computer
(Windows
compatible)
SW4D5C-GPPW-E or later 
GX Developer Version 7.10L (SW7D5C-GPPW-E) or later 
*2 
GX Developer Version 8 (SW8D5C-GPPW-E) or later 
*2 
GX Developer Version 8.18U (SW8D5C-GPPW-E) or later 
*2 
GX Developer Version 8.48A (SW8D5C-GPPW-E) or later 
*2  *1 
GX Developer Version 8.62Q (SW8D5C-GPPW-E) or later 
*2  *3 
GX Developer Version 8.68W (SW8D5C-GPPW-E) or later 
*4 
GX Developer Version 8.78G (SW8D5C-GPPW-E) or later 
*5 
GX Developer Version 8.89T (SW8D5C-GPPW-E) or later 
*5 *9
GX Works2 Version 1.24A (SW1DNC-GXW2-E) or later 
*5 *9
GX Works2 Version 1.25B (SW1DNC-GXW2-E) or later 
*6 *9
GX Works2 Version 1.56J (SW1DNC-GXW2-E) or later 
*6 *7
GX Works2 Version 1.98C (SW1DNC-GXW2-E) or later 
*8
GX Works2 Version 1.492N (SW1DNC-GXW2-E) or later 