For your individual requirements, Siemens has developed a sophisticated modular system: the fully modular connection for the I/O modules of the SIMATIC S7-300 and S7-400. With it, front connector modules, connection cables and connection modules can be combined as desired.
The fully modular connection reduces the wiring work and avoids sources of error that can arise from polarity reversal at the front connector and at the terminal strip in single wiring. Furthermore, connection modules with signal adaptation eliminate additional costs, since the wiring of further components is completely omitted, e.g., for individual coupling relays. The uniform and clear connection diagram reduces the test times and – in case of an error – facilitates the troubleshooting. By employing standard components, the configuration also becomes quicker and easier. The slightly higher material costs are more than compensated for by the time savings.