The freely programmable NA9372 fieldbus node adds a micro PLC to the decentralized, modular I/O system of the FnIO series from Wachendorff. The platform with dual Ethernet port and serial RS-232/RS-485 interface for configuration is equipped with a multitasking-capable 32-bit controller. The module supports the Modbus RTU slave serial interface and Modbus TCP client/server via an integrated network card. It can be used with expansion modules from the FnIO series. Programming is carried out in the Codesys V3.5 development environment. The Micro PLC and the expansion modules of the FnIO series are integrated into the Codesys development environment by importing the device description files. The integrated Modbus protocol allows integration into higher-level Scada and other monitoring systems. The web visualization function enables the display in a web browser.