Cpu Selection; Define The Basic User Program - Siemens Simatic SM331 Getting Started

6.1.1

CPU Selection

Choose the CPU 315-2DP for the sample project. (You can also use our
example for a different CPU). Then choose your CPU.
Figure 6-3
Click „Next"
6.1.2

Define the basic user program

Choose the SIMATIC language STL and select the following organization
blocks (OBs):
• OB1
• OB40
• OB82
OB1 is required in every project and is called cyclically.
OB40 is called when a hardware interrupt occurs.
OB 82 is called when a diagnostic interrupt occurs.
In case you use a module with diagnostic capabilities and OB82 is not in-
serted, the CPU changes to STOP mode when a diagnostic alarm occurs.
Figure 6-4
Click „Next"
STEP7 wizard „New Project", CPU selection
Program Cycle Organization Block
Hardware interrupt
Diagnostic interrupt
STEP7 wizard „New Project": Insert organization blocks
23 Getting Started SM331 AI 8x12bit Part1: 4-20mA
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