Test arrangement

A test arrangement for use in monitoring the status of an elongate cable is disclosed, the arrangement comprising a plurality of test modules 16 installed, in use, at intervals along a length of the cable 12, the modules 16 communicating with at least a control unit 20 via a distributed communications network 18. The arrangement may be used to test power cables used in the control of railway signalling systems. The test modules may be associated with function points 14 which may be, for example, transformers, signal lights or track point controllers. Parameters monitored may include resistance, insulation resistance, continuity and capacitance. The distributed communications network may use optical fibres or wireless communications. The test modules may also test for faults using Time Domain Reflectometry (TDR), and in particular spread spectrum TDR (SSTDR).