A Guide to Siemens SIMATIC S7-300 PLCs

A Brief History of Siemen’s SIMATIC Series

The SIMATIC line of programmable logic controllers (PLCs) has been a cornerstone of Siemens’ industrial automation offerings since its first release in 1958. Over the years, there have been four major generations of SIMATIC PLCs, each bringing significant advancements and improvements to the field of relay controls.

The SIMATIC G was released in 1959 and marked a turning point in the industry with its use of compact and energy-efficient transistors. This revolutionary technology allowed for more efficient and reliable control systems, paving the way for further developments in industrial automation.

In 1965, the SIMATIC N was introduced, utilising silicon as a conductive material. Although this may not have been considered a major generation change, it provided faster and more reliable devices, solidifying Siemens’ reputation as a leader in industrial automation equipment.

However, the most significant breakthrough came in 1973 with the release of the SIMATIC S3 line. This new generation of PLCs brought microprocessors and integrated circuits into the mix, allowing for unprecedented levels of programmability. For the first time, PLCs could be programmed via software, thanks to advancements in computer science and the introduction of sophisticated programming tools such as STEP 5.

Just six years later, Siemens once again raised the bar with the release of the SIMATIC S5 line. This generation of PLCs utilised STEP 5 as its programming tool, making it one of the first advanced computer-based PLC programming tools on the market. It first ran on CP/M and MS-DOS operating systems and eventually became available on Windows, further solidifying Siemens’ position as a pioneer in industrial automation.

S7-300 PLC: A Versatile Automation Solution

Moving to the present, the S7-300 PLC has been a popular choice among Siemens automation parts since its release in 1994. This mid-range controller is known for its versatility and cost-efficiency, making it suitable for extensive and complex process control tasks.

With 22 different versions available, the S7-300 offers a wide range of options for different industrial automation needs. These versions fall into four main categories: standard, compact, failsafe, and technology. The standard and compact CPUs are designed for small to medium plants with varying requirements, while the failsafe CPUs provide integrated safety-rated controls in one device. The technology CPUs are specially equipped for advanced motion control tasks.

Despite its popularity, Siemens has recently announced the start of the product phaseout for the S7-300. However, it will still be available as spare parts until 2033, giving existing users time to migrate to newer models such as the S7-1200 and S7-1500 PLCs. These advanced models offer even more features and capabilities for automation solutions.