The SIMATIC RF120C communications module is positioned to the left of the S7-1200 CPU. It enables a maximum of three RF120Cs to be operated on one S7-1200 CPU.

The reader is powered from the RF120C. The RF120C is provided with voltage via a screw-type terminal connector which is included in the scope of delivery.

For programming in the controller, a library is available with simple instructions such as Read/Write for accessing the transponder data. These instructions can also be used for other identification communication modules that are connected to the S7-1200 via Profibus/Profinet, e.g. for ASM 456 and RF180C. Furthermore, the library blocks can also be used for the SIMATIC S7-1500 so that the identification communication modules can be operated there via Profibus/Profinet.

Error messages and operating states (transponder in the field, transmission, etc.) are indicated additionally by means of LEDs behind the top cover of the RF120C. This makes commissioning and servicing considerably easier.

The RF120C features a sub D socket for connecting the reader. This also supplies the reader with voltage. The power supply of the reader is equipped with an electronic fuse. The maximum permissible current for a reader is 1 A.

The reader is connected to the RF120C with a pre-assembled reader cable which is available in different lengths. This 6GT2091-4Lxxx type cable can easily be extended with a type 6GT2891-4Fxxx cable in order to cover greater distances between the reader and the controller.

Communication between the SIMATIC RF120C and the controller is acyclic. Consequently, a very large amount of data can be transferred to/from the RF120C without overloading the bus cycle. This has advantages when transferring large volumes of data.