The S7-300 enables space-saving and modular configurations. In addition to the modules, only a DIN rail is required for hooking in the modules and screwing them into place.
This results in a rugged and EMC-compatible design.
The build-as-you-go backplane bus can be expanded by simply plugging in additional modules and bus connectors. The varied range of the S7-300 can also be used for centra lexpansions or the construction of distributed structures with ET 200M; thereby producing very cost-effective spare parts handling.
If the automation task requires more than 8 modules, the central controller (CC) of the S7-300 can be expanded using expansion units (EUs) Up to 32 modules can be used in the centralrack and up to 8 per expansion unit. Interface modules(IMs) handle communication between the individual racksautonomously. In the case of plants covering wide areas, CCs/EUs can also be installed at greater distances from eachother (up to 10 m).
In a single-tiered configuration, this results in a maximumconfiguration of 256 I/O, and in multi-tiered configurations upto 1024 I/O. In distributed configurations with PROFIBUS DP,65536 I/O connections are possible (up to 125 stations, suchas ET 200M via IM 153). The slots are freely addressable, thatis, there are no slot rules.
The extensive range of S7-300 modules is also used in distributedautomation solutions.
The ET 200M I/O system that hasthe same construction as the S7-300 can be connected via Interface modules not only to PROFIBUS but also to PROFINET.