Program Processing - Siemens S5-100U User Manual

Introduction to STEP 5
7.4

Program Processing

Some of the organization blocks (OBs) are responsible for structuring and managing the control
program.
These OBS can be grouped according to the following assignments:
• OBs for START-UP program processing
• One OB for cyclic program processing
• OBs for time-controlled program processing
• OBs for (process) interrupt-driven program processing
The S5-100U has additional OBs whose functions are similar to those of integral function blocks
(e.g., PID control algorithm). These OBs are described in chapter 9.
Section 7.3.1 summarizes all of the OBs.
Comparing Programming Possibilities for CPU 100, CPU 102, and CPU 103
CPU
Cyclical
Interrupt-driven
Time-controlled
Integral FBs
Graph 5
Programmable FBs
Beginning with section 7.4.2, you learn which special organization blocks each of the CPUs has
available to perform the programming tasks described in Table 7-5. You also learn which pre-
cautions you need to take when you program.
7-18
Table 7-5. Programming Possibilities
CPU 100
Yes
No
No
No
(for 8MA02 and higher)
No
No
CPU 102
Yes
No
(for 8MA02 and higher)
No
(for 8MA02 and higher)
Yes
No
No
S5-100U
CPU 103
Yes
Yes
Yes
Yes
Yes
Yes
EWA 4NEB 812 6120-02