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AH500 Programming Manual 
Contents 
Chapter 1 Introduction 
1.1  Overview .................................................................................................. 1-2 
1.1.1  Related Manuals ............................................................................... 1-2 
1.1.2  Model Description .............................................................................. 1-2 
1.2  Software ..................................................................................................1-10 
1.2.1  Program Editor .................................................................................1-10 
1.2.2  Program Organization Units and Tasks ............................................ 1-11 
Chapter 2 Devices 
2.1  Introduction of Devices ............................................................................. 2-2 
2.1.1  Devise List ......................................................................................... 2-2 
2.1.1.1 AH500 Basic CPU Modules (AHCPU500/510/520/530) ................... 2-2 
2.1.1.2 AH500 Advanced CPU Modules (AHCPU501/511/521/531) ............ 2-3 
2.1.2  Basic Structure of I/O Storages ......................................................... 2-4 
2.1.3  Relation between the PLC Action and the Device Type .................... 2-4 
2.1.4  Latched Areas in the Device Range .................................................. 2-5 
2.2  Functions of Devices ................................................................................ 2-6 
2.2.1  Values and Constants ........................................................................ 2-6 
2.2.2  Floating-point Numbers ..................................................................... 2-7 
2.2.2.1  Single-precision Floating-point Numbers ................................... 2-7 
2.2.2.2  Double-precision Floating-point Numbers .................................. 2-8 
2.2.2.3  Decimal Floating-point Numbers ................................................ 2-9 
2.2.3  Strings ............................................................................................... 2-9 
2.2.4  Input Relays .....................................................................................2-10 
2.2.5  Output Relays .................................................................................. 2-11 
2.2.6  Auxiliary Relays ................................................................................ 2-11 
2.2.7  Special Auxiliary Relays ...................................................................2-12 
2.2.8  Refresh Time of Special Auxiliary Relays .........................................2-38 
2.2.9  Stepping Relays ...............................................................................2-46 
2.2.10  Timers ...........................................................................................2-47 
2.2.11  Counters .......................................................................................2-48 
2.2.12  32-bit Counters .............................................................................2-50 
2.2.13  Data Registers ..............................................................................2-51 
2.2.14  Special Data Registers .................................................................2-52