Mitsubishi Electronics FX3G User Manual

5

FX

3S

/FX

3G

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3GC

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3U

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3UC

Series

Programming Manual - Basic & Applied Instruction Edition

Table of Contents

5. How to Specify Devices and Constants to Instructions

153

5.1 Numeric Values Handled in PLC (Octal, Decimal, Hexadecimal and Real Numbers) ......................... 153

5.1.1  Types of numeric values ....................................................................................................................... 153
5.1.2  Conversion of numeric values............................................................................................................... 154
5.1.3  Handling of numeric values in floating point operations........................................................................ 155

5.2 Specification of Constants K, H and E (Decimal, Hexadecimal and Real Number)............................. 157

5.2.1  Constant K (decimal number) ............................................................................................................... 157
5.2.2  Constant H (hexadecimal number) ....................................................................................................... 157
5.2.3  Constant E (real number)...................................................................................................................... 157

5.3 Character Strings ................................................................................................................................. 158

5.3.1 Character string constant ("ABC")......................................................................................................... 158
5.3.2 Character string data............................................................................................................................. 158

5.4  Specification of Digits for Bit Devices (Kn[ ]***).................................................................................... 159
5.5  Bit Specification of a Word Device (D[ ].b) ........................................................................................... 160
5.6  Direct Specification of Buffer Memory (U[ ]\G[ ]) .................................................................................. 160
5.7 Indexing................................................................................................................................................ 161

5.7.1  Indexing in basic instructions ................................................................................................................ 161
5.7.2  Indexing in applied instructions ............................................................................................................. 162
5.7.3  Indexing example for instruction with limited number of use................................................................. 164

6. What to Understand before Programming

166

6.1 How to Read Explanation of Instructions ............................................................................................. 166
6.2 Cautions on Creation of Fundamental Programs................................................................................. 169

6.2.1 Programming procedure and execution order....................................................................................... 169
6.2.2 Double output (double coil) operation and countermeasures ............................................................... 170
6.2.3 Circuits which cannot be programmed and countermeasures .............................................................. 171

6.3 I/O Processing and Response Delay ................................................................................................... 171
6.4 Mutual Relationship Among Program Flow Control Instructions.......................................................... 172
6.5 General Rules for Applied Instructions................................................................................................. 174

6.5.1 Expression and operation type of applied instructions.......................................................................... 174
6.5.2 Handling of general flags ...................................................................................................................... 176
6.5.3 Handling of operation error flag............................................................................................................. 178
6.5.4 Handling functions of extension flag ..................................................................................................... 178
6.5.5 Limitation in the number of instructions and limitation in simultaneous instruction instances............... 179

6.6 Symbolic information storage and block password .............................................................................. 180

6.6.1 Storage of symbolic information............................................................................................................ 180
6.6.2 Block password ..................................................................................................................................... 180

7. Basic Instruction

181

7.1  LD, LDI ................................................................................................................................................. 183
7.2 OUT...................................................................................................................................................... 185
7.3  AND, ANI.............................................................................................................................................. 188
7.4  OR, ORI ............................................................................................................................................... 191
7.5 LDP, LDF, ANDP, ANDF, ORP, ORF .................................................................................................. 194
7.6 ORB ..................................................................................................................................................... 200
7.7 ANB...................................................................................................................................................... 201
7.8  MPS, MRD, MPP ................................................................................................................................. 202
7.9 MC, MCR ............................................................................................................................................. 205
7.10 INV ..................................................................................................................................................... 208
7.11  MEP, MEF.......................................................................................................................................... 209
7.12 PLS, PLF............................................................................................................................................ 211
7.13 SET, RST ........................................................................................................................................... 214
7.14 NOP ................................................................................................................................................... 217
7.15 END.................................................................................................................................................... 218
7.16 Number of Instruction Steps and Specified Devices .......................................................................... 219