5-1
Chapter 5 Understanding Common Devices
Table of Contents
5.1. Introduction .................................................................................................. 5-2
5.2. Common Devices ........................................................................................... 5-2
5.2.1. Functions of Common Devices ..................................................................... 5-2
5.2.2. Device List ................................................................................................ 5-2
5.2.3. Latched Devices......................................................................................... 5-4
5.2.4. Input Relays (X) ........................................................................................ 5-5
5.2.5. Output Relays (Y) ...................................................................................... 5-5
5.2.6. Auxiliary Relays (M) ................................................................................... 5-6
5.2.7. Special Auxiliary Relays (SM/AM) ................................................................. 5-6
5.2.8. Data Registers (D) ..................................................................................... 5-6
5.2.9. Special Data Registers (SR/AR) ................................................................... 5-7
5.2.10. Link Registers (L)....................................................................................... 5-7
5.2.11. Stepping Relays (S) ................................................................................... 5-7
5.2.12. Timers (T) ................................................................................................ 5-7
5.2.13. Counters (C) ............................................................................................. 5-9
5.2.14. 32-bit Counters (HC/AC) ........................................................................... 5-10
5.2.15. Index Registers (E) .................................................................................. 5-10
5.2.16. Values and Constants (K, 16#) .................................................................. 5-11
5.2.17. Floating-point Numbers (F, DF) ................................................................. 5-12
5.2.18. Strings (“$”) ........................................................................................... 5-14
5.3. EtherCAT Symbols ....................................................................................... 5-16
5.4. Symbols ....................................................................................................... 5-16
5.4.1 Application of Symbols ............................................................................. 5-16
5.4.2 Classes ................................................................................................... 5-16
5.4.3 Data Types ............................................................................................. 5-17
5.4.4 Using Devices, Symbols and Instructions .................................................... 5-18
5.4.5 Modifying a Symbol with an Index Register ................................................. 5-19
5.5. User-defined Data Type (ENUM) .................................................................. 5-20