Small transmitters connected by cable are installed at 50cm intervals on the outer guide trough side links. The so-called beacons transmit their positions to a single antenna fixed to the floating moving end. The system uses the relative position of the beacons to the antenna and the transmitted position to calculate the trolley position. It is then sent to the customer control system via Profinet. This provides information for the EC. PR push/pull force monitoring system. It also positions the crane trolley precisely. The repeatability envisioned is indicated to be +/-5mm!