SIEMENS SIMATIC S7-1200 HARDWARE SETUP

PLC CPU: 

It used a SIMATIC S7-1200 CPU 1215C, which is a compact programmable logic controller. In the context of PLCs, the term "CPU" refers to the central processing unit of the controller. The CPU is the brain of the PLC, executing control instructions contained in the user program. 

A PLC CPU typically consists of the processor, the memory system, and, in many cases, integrated power supply circuits to manage its own power requirements. However, this does not mean it contains the power supply for the entire PLC system.

Here's how it breaks down:

• Processor: Executes the control program that has been loaded into the PLC.
• Memory System: Stores the control program, as well as the data required for executing the program, which includes the status of inputs, outputs, and intermediate calculations.
• Power Supply (Internal): Provides the necessary voltages to the CPU and sometimes to some of the internal components such as integrated I/Os. This is not to be confused with the main power supply unit (PSU) that powers the entire PLC system. 

Power Supply: 

While the PLC CPU has an integrated power circuit for its own operation, the entire PLC system requires an external power supply unit. This PSU provides the necessary power to all components of the PLC system, including the CPU, Communication Modules, and other peripherals. An MCB (Miniature Circuit Breaker) is included for overcurrent protection of the system.

Communication Module: 

The 6GK5005-0BA00-1AB2 SCALANCE XB005, an unmanaged industrial Ethernet switch, is part of this setup. It known as ethernet switch. This unmanaged industrial Ethernet switch facilitates communication between various devices within the PLC system. PROFINET runs over standard Ethernet, and devices like PLCs and HMIs that use PROFINET will communicate through the Ethernet switch. The switch effectively orchestrates the flow of PROFINET packets between devices, allowing them to interact as part of an integrated automation system.

HMI Panel: 

A KTP400 Basic panel is included in this setup, which serves as an interface for user interaction. This Human-Machine Interface (HMI) allows operators to interact with the PLC, offering a user-friendly window into the system's operations. It's where the complex language of machines meets the simplicity of touch control.

Field Devices:

These devices are referred to as 'field devices' in automation because they are located in the field, i.e., the operational environment of the PLC system. When connecting these devices to a PLC:

• The inputs are referred to as 'channels' to which field devices send signals to the PLC eg. Switches, Sensors.
• The outputs are channels through which the PLC sends signals to control field devices eg. LEDs, Actuators.

Optional: Additional I/O Modules: 

If the integrated I/Os on the CPU 1215C are not sufficient, additional I/O modules such as SM 1221 Digital Input Modules and SM 1222 Digital Output Modules can be added to expand the system's capabilities.