The serial interface module allows devices with RS-485, RS-422 or RS-232 interface (optional) to be connected to the WAGO I/O SYSTEM 750/753. This allows gateways from the fieldbuses supported by the WAGO I/O system 750/753 to a serial interface to also be created. The module does not support higher protocol layers. The communication is completely transparent to the corresponding fieldbus master. This ensures a wide range of applications for the serial interface module. Any communication protocols that may be required can be flexibly programmed into the fieldbus master. The 8192-byte receive buffer size allows the module to be used, even at high transmission rates. At low data transmission rates, the receive data can be evaluated in tasks with low priority without any loss of data.