S5-95F
Design, Functions and Operation
2.4
The Programmable Controllers' Principle of Operation
This section describes how the controller processes your program.
2.4.1
Functional Units
Figure 2-3. Functional Units of a Basic Programmable Controller
a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a
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a a a a a a a a a a a a a a a a a a a a a a a a
External
I/O bus
Functional
modules
Operating
system
(ROM)
Arithmetic
unit
Processor
Timers
Counters
Flags
PIQ
Memory
submodule
(EPROM)
Serial
interface
Input
modules
(digital,
analog)
Output
modules
(digital,
analog)
CPU
Control
program
and data
blocks
(RAM)
Onboard
inputs
(digital,
interrupt,
counter)
Onboard
outputs
(digital)
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a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a
Basic unit
a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a
Onboard I/Os
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
a a a a a a a a
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a a a a a a a a
a a a a a a a a
a a a a a a a a
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a a a a a a a a
PII
Redundant
link via
fiber optic
cable
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
Failsafe and non-failsafe modules
EWA 4NEB 812 6210-02
2-5