MULTIPLEX COMMUNICATION SYSTEM AND WORK MACHINE

Provided are a multiplex communication system and a work machine, in which opportunities to attach and detach an optical communication cable can be reduced, thereby suppressing the occurrence of communication failure due to dust or the like. In an electronic component mounting device, a multiplexing device 5 of a head section which is attachable to and detachable from a Y-axis slider is connected to a multiplexing device 1 through an electric communication cable 121. In this way, the multiplexing device 5, from which the cable is likely to be removed, is connected through the electric communication cable 121 for which the communication failure due to dust or the like is relatively unlikely to occur. On the other hand, the multiplexing devices 1 and 3 , from which cables are less likely to be removed, are connected through the optical communication cable 120. The multiplexing device 1 separates data directed to the input and output device 271, among frame data FRMD1 received from the multiplexing device 3, multiplexes only data directed to the multiplexing device 5 from the multiplexing device 3, and transfers the multiplexed data to the multiplexing device 5 by the electric communication cable 121.