For maximum flexibility, Simatic RF166C supports the setup of a Profibus line topology without additional Y connectors through two connectors each for Profibus and power supply. This means that every type of application can be implemented quickly and cost-effectively. Grounding is achieved simply and reliable via a fixing screw, so that the structure is optimally secured against electromagnetic interferences. In addition to read and write transponder data, the function block in the Simatic controller can be used to access configuration and diagnostic data. In addition, web-based management (WBM) is now also available for a Profibus module via an additional Ethernet connector. Combined with adjustable and parameterizable diagnostics and the display of error messages and operating status via LED (light-emitting diode), this makes commissioning, troubleshooting and servicing much easier. The integrated logbook can be used for error analysis, even months later. The transparent cover caps for the Profibus address, makes these visible also when the module is installed. This facilitates commissioning and diagnosis in addition.