Quaternized cellulose ethers suitable for personal care products are described. At least one LAB includes a logic element configurable to arithmetically combine a plurality of binary input signals in a plurality of stages. The adapter includes a plurality of device ports. The subscriber can then elect to view the programming as a pay-per-view event. This is achieved in that an evaluation unit regularly evaluates a saturation voltage of the optocoupler at the output of the optocoupler in relation to a reference threshold when the optocoupler is wired and generates a warning signal when the saturation voltage exceeds the reference threshold. The DPF also may be located ahead of the LNT.