1.2.2. Fundamental concepts

1.2.2.1. Memory Overview

Memory layout and addressing

1.2.2.1.1. Input and Output

S7-1200 integrated IO mapping

PLC tags organization

1.2.2.1.2. Merker

Merker

1.2.2.1.3. Data Block

Create new Data Block

Using DB variables

1.2.2.2. POU: Program Organization Unit

1.2.2.2.1. Organization Block

Organization Blocks

1.2.2.2.2. Function

Create and use a function as code organization

1.2.2.2.3. Function Block

1.2.2.3. PLC programming languages

The standard IEC 61131-3 define 5 programming languages for PLC:

• IL: Instruction List (STL in Step7)
• LD: Ladder Diagram (LAD in step7)
• ST: Strucured Text (SCL in Siemens)
• SFC : Sequential Fucntion Chart
• FBD: Fucntion Block Diagram