High Quality Content by WIKIPEDIA articles! The Simatic S5 PLC is an automation system based on Programmable Logic Controllers. It is manufactured and sold by Siemens AG. Such automation systems control process equipment and machinery used in manufacturing. This product line is considered obsolete, as the manufacturer has since replaced it with their newer Simatic S7 PLC. However, the S5 PLC still has a huge installation base in factories around the world. Most automation systems integrators still have the ability to provide support for the platform.