This article considers the output synchronisation of a class of networked agents. Each agent is a passive system. Local information, used by each agent to adjust its movement, forms a network with switching adjacent topology. First, we consider the asymptotic stability of switched non-linear time-varying systems with delayed measurement feedback by using multiple Lyapunov function. A Barbalat-like lemma is obtained. Then the result is applied to the output synchronisation of a class of networked passive systems with switching topology. A verifiable sufficient condition is presented.