Siemens PLC Guides

Siemens PLC CPUs are categorized into different series, each designed for specific applications and requirements. Here's a brief comparison of some popular models:

• S7-1200:
• • Designed for basic automation tasks.
  • Compact and cost-effective.
  • Suitable for small to medium-sized applications.
  • Limited memory and fewer communication options compared to advanced models.
• S7-1500:
• • Advanced controller for complex automation tasks.
  • Offers higher processing power and memory.
  • Supports more I/O modules and communication options.
  • Integrated motion control capabilities.
• S7-1500:
• • Advanced controller for complex automation tasks.
  • Offers higher processing power and memory.
  • Supports more I/O modules and communication options.
  • Integrated motion control capabilities.
• S7-300:
• • Versatile and widely used for medium-sized applications.
  • Modular design allows flexibility in configuration.
  • Supports a variety of communication protocols.
• S7-300:
• • Versatile and widely used for medium-sized applications.
  • Modular design allows flexibility in configuration.
  • Supports a variety of communication protocols.
• S7-400:
• • High-performance controller for large-scale and complex systems.
  • Designed for process automation and high-speed applications.
  • Offers extensive networking and communication capabilities.

Each series has its strengths, and the choice depends on the specific requirements of your project, such as scalability, processing power, and communication needs

Consider the following when choosing a CPU

• Do you require any special communication such as IEC communications? Check the data sheet of the entry level PLC CPU and move up until you find a PLC that is capable.
• Do you require any special controls such as advanced PID blocks? Check the data sheet.
• Do you require any special functions such as servo motor functions? Check the data sheet for capability and quantity.
• Is your CPU for a standalone machine or site wide spervisory control. For single machinery future expansion is not likely, but for process plants, future expansion is inevitable?
• Do you need to communicate to many devices over a fieldbus technology? Check the data sheet for maximum read and write instructions.
• Do you need to SIL rated safety functions?
• In which country will it be used? Local brands support local technologies better than other countries/continents, eg Siemens supports Profibus in Europe & Allen Bradley supports Foundaton Fieldbus in the USA.