User Manual

Table of contents
Easy Book
8 Manual, 03/2014, A5E02486774-AF
3.10 Create an HMI screen ................................................................................................................. 49
3.11 Select a PLC tag for the HMI element ........................................................................................ 50
4 PLC concepts made easy ..................................................................................................................... 51
4.1 Tasks performed every scan cycle ............................................................................................. 51
4.2 Operating modes of the CPU ...................................................................................................... 52
4.3 Execution of the user program .................................................................................................... 53
4.3.1 Processing the scan cycle in RUN mode .................................................................................... 54
4.3.2 OBs help you structure your user program ................................................................................. 55
4.3.3 Event execution priorities and queuing ....................................................................................... 55
4.4 Memory areas, addressing and data types ................................................................................. 58
4.4.1 Data types supported by the S7-1200 ........................................................................................ 60
4.4.2 Addressing memory areas .......................................................................................................... 62
4.4.3 Accessing a "slice" of a tagged data type ................................................................................... 64
4.4.4 Accessing a tag with an AT overlay ............................................................................................ 65
4.5 Pulse outputs .............................................................................................................................. 67
5 Easy to create the device configuration ................................................................................................. 71
5.1 Detecting the configuration for an unspecified CPU ................................................................... 72
5.2 Adding a CPU to the configuration .............................................................................................. 73
5.3 Changing a device ...................................................................................................................... 74
5.4 Adding modules to the configuration ........................................................................................... 74
5.5 Configuring the operation of the CPU and modules ................................................................... 76
5.5.1 System memory and clock memory provide standard functionality ............................................ 77
5.6 Configuring the IP address of the CPU ....................................................................................... 80
5.7 Protecting access to the CPU or code block is easy .................................................................. 82
5.7.1 Know-how protection ................................................................................................................... 84
5.7.2 Copy protection ........................................................................................................................... 85
6 Programming made easy ...................................................................................................................... 87
6.1 Easy to design your user program .............................................................................................. 87
6.1.1 Use OBs for organizing your user program ................................................................................ 89
6.1.2 FBs and FCs make programming the modular tasks easy ......................................................... 90
6.1.3 Data blocks provide easy storage for program data ................................................................... 92
6.1.4 Creating a new code block .......................................................................................................... 92
6.1.5 Creating reusable code blocks .................................................................................................... 93
6.1.6 Calling a code block from another code block ............................................................................ 94
6.2 Easy-to-use programming languages ......................................................................................... 94
6.2.1 Ladder logic (LAD) ...................................................................................................................... 94
6.2.2 Function Block Diagram (FBD) ................................................................................................... 95
6.2.3 SCL overview .............................................................................................................................. 96
6.2.4 SCL program editor ..................................................................................................................... 96
6.3 Powerful instructions make programming easy .......................................................................... 98
6.3.1 Providing the basic instructions you expect ................................................................................ 98
6.3.2 Compare and Move instructions ............................................................................................... 100
6.3.3 Conversion instructions ............................................................................................................. 101