SIMATIC ET 200SP, Base Unit BU20-P12+A4+0B, BU Type B0, Push-In terminals, with 4 AUX terminals, bridged to the left, dimensions: 20 mm x 117 mm. The SIMATIC ET 200SP is a modular, scalable, and highly flexible decentralized peripheral system. Its small footprint makes it particularly suitable for installation in compact machine-mounted control cabinets. The modules can either be plugged directly into an ET 200SP CPU or connected to a central controller via PROFINET or PROFIBUS. The SIMATIC ET 200SP can be expanded with up to 64 peripheral modules, which can be combined in any configuration. The system offers a very extensive range of components. Many modules are also available in different versions, significantly enhancing scalability in terms of functionality and price. In addition to modules with standard functionality (ST), those with extended functionality and diagnostics (HF High Feature / HS High Speed) are also available. For price-sensitive applications, modules with basic functionality (BA) are offered. The advantage of the ET 200SP system lies in its ease of use, such as the free choice of PROFINET connection technology via the bus adapter, tool-free wiring through Push-In technology, improved accessibility of wiring due to the new arrangement of the spring openings next to the corresponding conductor openings, and channel-specific diagnostic functions. The ability to perform module and terminal box changes during operation, known as hot-swapping, ensures the availability and productivity of the machine. The scalable and cost-optimized configuration of an ET 200SP station is ensured by the comprehensive range of signal modules. In addition to digital and analog input and output modules, fault-tolerant variants for applications up to SIL 3 / PLe are also available.