With the Simatic RF680A, Siemens is offering an adaptive antenna for its RF650R, RF680R und RF685R UHF readers. The variable-polarization antenna (linear or circular) simplifies the commissioning and planning of RFID applications, and the automatic antenna adjustment facility makes for increased read and write reliability. These benefits create enormous flexibility for users, as it is frequently not possible to know during the planning phase whether linear or circular polarizing antennas will be required. The RF650R and RF680R readers have ports for four external antennas, allowing the implementation of four read points. In conjunction with the RF685R, two read points are possible.