Introducing the S7-200 Micro PLC
1-5
S7-200 Programmable Controller System Manual
A5E00066097-02
1.2 Major Components of the S7-200 Micro PLC
An S7-200 Micro PLC consists of an S7-200 CPU alone or with a variety of
optional expansion modules.
S7-200 CPU
The S7-200 CPU combines a central processing unit (CPU), power supply, and
discrete I/O points into a compact, stand-alone device.
• The CPU executes the program and stores the data for controlling the
automation task or process.
• The digital inputs and outputs are the system control points: the inputs monitor
the signals from the field devices (such as sensors and switches), and the
outputs control pumps, motors, or other devices in your process.
• The power supply provides electrical power for the CPU and for any expansion
module that is connected.
• The communications port(s) allow you to connect the CPU to a programming
device or to other devices.
• Status lights provide visual information about the CPU mode (RUN or STOP),
the current state of the local I/O, and whether a system fault has been
detected.
• Additional I/O points can be added to the CPU with expansion modules. (The
CPU 221 is not expandable.)
• Higher performance communications can be added with expansion modules.
• Some CPUs provide a real-time clock as a built-in feature, while other CPUs
have an optional real-time clock cartridge.
• An optional plug-in serial EEPROM cartridge provides a means to store CPU
programs and transfer programs from one CPU to another.
• An optional plug-in battery cartridge provides extended retention of data
memory in RAM.
To Next Page
Loading...
