A bilateral controller is used to transmit and share haptic information between a master system and a slave system. In a transmission system, the bilateral controller encounters problems in the event of data packet loss and/or disconnections. In this study, a master/slave simulator and environmental data memory are used to solve the problems. In the case of normal operation, the environmental data memory stores force data in a remote side. The control system is operated by the environmental data memory and master/slave simulator when the communication lines are disconnected.