Difference between AB PLC5 Siemens S5 Controllogix gateway Siemens S7

Comparing Allen-Bradley (AB) PLC-5, Siemens S5, ControlLogix, and Siemens S7 involves looking at different generations and brands of PLCs (Programmable Logic Controllers). Each of these PLC systems has unique features and capabilities tailored to specific industrial automation needs. Here’s an overview of their differences:

Allen-Bradley PLC-5

• Generation: Considered a legacy system, predominantly used in the 1980s and 1990s.
• Communication: Primarily used Data Highway Plus (DH+) and Remote I/O. Lacked native Ethernet support.
• Programming: Programmed using ladder logic; software used was RSLogix 5.
• Applications: Widely used in various industries for robust control applications but is now mostly phased out in favor of newer systems.

Siemens S5

• Generation: Another legacy system, comparable to the AB PLC-5 era.
• Communication: Utilized proprietary Siemens communication protocols and did not originally support Ethernet.
• Programming: Used STEP 5 software for programming. The programming language was primarily statement list (STL).
• Applications: Extensively used in European markets and varied industrial applications during its time.

Allen-Bradley ControlLogix

• Generation: Current generation PLC from Rockwell Automation (Allen-Bradley).
• Communication: Offers integrated Ethernet/IP support and other networks like ControlNet and DeviceNet.
• Programming: Uses RSLogix 5000/Studio 5000 software, supporting multiple programming languages like ladder logic, function block diagram, and structured text.
• Applications: Designed for complex and large-scale applications, offering significant improvements in performance, communication, and scalability compared to PLC-5.

Siemens S7

• Generation: The modern series of PLCs from Siemens.
• Communication: Supports a range of communication options, including Profinet (Siemens’ industrial Ethernet standard).
• Programming: Programmed using STEP 7 (TIA Portal) software, supporting various programming languages.
• Applications: Widely used in various industries for both simple and complex automation tasks. Known for its scalability and performance.

Gateway Considerations

When integrating these systems, especially older ones like PLC-5 and S5 with modern systems like ControlLogix and S7, gateways are often required. These gateways translate the communication protocols from one system to another, allowing for data exchange and interoperability. This is crucial in facilities where legacy and modern systems coexist and need to communicate.

Summary

• Legacy vs. Modern: PLC-5 and S5 represent the legacy generation, while ControlLogix and S7 are current-generation PLCs.
• Communication and Programming: Older systems have more limited communication capabilities and programming environments compared to modern PLCs, which offer versatile communication options (including Ethernet) and multi-language programming.
• Brand-Specific Features: Each brand (Allen-Bradley and Siemens) has unique features and strengths, making them suitable for different industrial environments and applications.

In transitioning from older systems to newer ones, it’s important to consider factors like communication capabilities, programming environments, and overall system requirements to ensure seamless integration and operation.