GE PACSystems RX7i - Page 5

Contents
ii PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C
3.2 Reference Memory .................................................................................................................. 37
3.2.1 Word (Register) References ................................................................................................................................. 37
3.2.2 Bit (Discrete) References ....................................................................................................................................... 39
3.3 User Reference Size and Default ......................................................................................... 40
3.3.1 %G User References and CPU Memory Locations ....................................................................................... 40
3.4 Genius Global Data .................................................................................................................. 41
3.5 Transitions and Overrides ..................................................................................................... 42
3.6 Retentiveness of Logic and Data ......................................................................................... 43
3.7 Data Scope ................................................................................................................................ 44
3.8 System Status References .................................................................................................... 45
3.8.1 %S References............................................................................................................................................................ 46
3.8.2 %SA, %SB, and %SC References ......................................................................................................................... 47
3.8.3 Fault References ....................................................................................................................................................... 49
3.9 How Program Functions Handle Numerical Data ............................................................ 51
3.9.1 Data Types ................................................................................................................................................................... 51
3.9.2 Floating Point Numbers.......................................................................................................................................... 53
3.10 User Defined Types (UDTs) ................................................................................................... 55
3.10.1 Working with UDTs .................................................................................................................................................. 55
3.10.2 UDT Properties ........................................................................................................................................................... 55
3.10.3 UDT Limits.................................................................................................................................................................... 56
3.10.4 RUN Mode Store of UDTs ....................................................................................................................................... 56
3.10.5 UDT Operational Notes .......................................................................................................................................... 57
3.11 Operands for Instructions ..................................................................................................... 58
3.12 Word-for-Word Changes ....................................................................................................... 60
3.12.1 Exception: Symbolic Variables ............................................................................................................................. 60
Chapter 4 Ladder Diagram (LD) Programming ............................................................................. 61
4.1 Advanced Math Functions ..................................................................................................... 62
4.1.1 Exponential/Logarithmic Functions .................................................................................................................. 63
4.1.2 Square Root ................................................................................................................................................................. 64
4.1.3 Trig Functions ............................................................................................................................................................. 65
4.1.4 Inverse Trig – ASIN, ACOS, and ATAN ............................................................................................................... 66
4.2 Bit Operation Functions ........................................................................................................ 67
4.2.1 Data Lengths for the Bit Operation Functions .............................................................................................. 68
4.2.2 Bit Position .................................................................................................................................................................. 69
4.2.3 Bit Sequencer ............................................................................................................................................................. 70
4.2.4 Bit Set, Bit Clear ......................................................................................................................................................... 73