AbstractFor multi-agent systems with directed and time-varying communication graph and limited quantized communication data rate, distributed average consensus is investigated. We first give the corresponding convergence results for the case of directed fixed communication network, and then, propose a feedback-based distributed consensus protocol for the time-varying topology case to deal with the inconsistency between the internal state of each agent's encoder and the output of its neighbors’ decoder. It is shown that if the communication graph is directed, balanced and periodically connected, then exponential average consensus can be achieved by using merely one bit information exchange between each pair of adjacent agents at each time step.