SIMATIC S7-300, front connector for signal modules with screw contacts, 20-pin, 100 pieces per packaging unit SIMATIC ET 200M is a modular and universally applicable I/O system for the control cabinet in IP20, which can be used both as a central I/O on an S7-300 and in a decentralized configuration on a PROFINET or PROFIBUS ET 200M interface module. Up to 12 IO modules can be plugged into each station. The standardized structure of all modules makes logistics and spare parts management significantly easier. Accessories for SIMATIC S7-300