Chapter 2 Devices Table of Contents 2.1 Introduction of Devices ............................................................................. 2-2 2.1.1 Devise List ......................................................................................... 2-2 2.1.2 Basic Structure of I/O Storages ......................................................... 2-3 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 ...................................................................2-11 2.2.8 Refresh Time of Special Auxiliary Relays .........................................2-42 2.2.9 Stepping Relays ...............................................................................2-50 2.2.10 Timers ..............................................................................................2-51 2.2.11 Counters ...........................................................................................2-53 2.2.12 32-bit Counters .................................................................................2-54 2.2.13 Data Registers .................................................................................2-55 2.2.14 Special Data Registers .....................................................................2-56 2.2.15 Refresh Time of Special Data Registers ..........................................2-82 2.2.16 Additional Remarks on Special Auxiliary Relays and Special Data Registers ..........................................................................................2-83 2.2.17 Link Registers ..................................................................................2-96 2.2.18 Index Registers ................................................................................2-96 2-1