Block diagram of the CTT system. The AFE are the analog front-end boards, which discriminate and digitize the signals from the VLPC's. The Mixing box sorts signals from ribbon oriented to trigger sector oriented. The DFE are the digital front-end boards, which find the CFT tracks or the preshower clusters. The broadcaster systems form the L1 trigger and/or deliver the tracks and clusters information to the L2 preprocessors.