This paper proposes and analyzes a communication mechanism capable of supporting real-time RPC(Remote Procedure Call) which is based on request-acknowledgment-reply semantic. As an enhanced protocol of TDMA-implemented Ethernet, the proposed CS(Communication System) dynamically schedules RPC-related messages according to their attributes, making a network schedule be easily combined with a server schedule. As RPC schedule produced by combining server schedule and communication schedule can obviate the waste computation time at the server, more real-time RPC requests can meet their timing constraints. Simulation result shows that the RPC over the proposed CS outperforms those over token bus and TDMA on the various network parameters, such as RPC arrival time, service time and slack.