A multiplexing communication system that multiplexes multiple data of devices comprising an electromagnetic motor provided in a movable section of a mounter using optical multiplexing devices, and transfers the resulting data, toward an optical multiplexing device, wherein, while transferring the data relating to a mounting operation between each device using the multiplexing communication system, the mounter performs the operation of mounting electronic components on a circuit board using the movable section, wherein the multiple data belong to multiple types of data which have a different stipulated data transfer rate and required data processing time and that performs communication through wired communication, and wherein the system comprises: a transmitting side (22; 201) that includes an error setting means (211, 212, 213) configured to perform setting processing for error detection in accordance with the data transfer rate and the data processing time on each of the multiple data, and a multiplexing means (5; 219) configured to multiplex the multiple pieces of data as divided by the frame division section on which the setting processing for the error detection is performed by the error setting means, into a multiplex data string; and a receiving side (20; 301) that includes a restoration means configured to restore the multiple data from the multiplex data string, comprising a demultiplexing means (3; 319) configured to demultiplex the multiplex data string into multiple pieces of frame data, and an error checking means (311, 312, 313, 334) configured to perform error detection processing or error detection/correction processing in accordance with the setting processing by the error setting means, on each of the multiple data that result from the composition, wherein at least one of the transmitting side and the receiving side includes a processing circuit (45, 86; 91-94) configured to perform at least one type of processing operation among I/O control processing, sensor information fetching processing, communication protocol conversion processing, image input processing that fetches an output of an image element, and communication processing by a slave on a control network, wherein the processing circuit of the transmission side is configured to function as the multiplexing means and/or the processing circuit of the receiving side is configured to function as the restoration means wherein the multiple data include a detection signal that is output from a sensor element and an encoder signal that is output from an encoder which detects displacement of the electromagnetic motor, characterised in that the receiving side includes notifying means configured to notify a drive control section that controls the electromagnetic motor according to the encoder signal, after an activation delay time, which is a delay time set to start from a point in time when the multiplex means and the restoration means are activated, has elapsed, and wherein the drive control section, as a result of this notifying, activates an amplification section that controls the electromagnetic motor. a transmitting side (22; 201) that includes an error setting means (211, 212, 213) configured to perform setting processing for error detection in accordance with the data transfer rate and the data processing time on each of the multiple data, and a multiplexing means (5; 219) configured to multiplex the multiple pieces of data as divided by the frame division section on which the setting processing for the error detection is performed by the error setting means, into a multiplex data string; and a receiving side (20; 301) that includes a restoration means configured to restore the multiple data from the multiplex data string, comprising a demultiplexing means (3; 319) configured to demultiplex the multiplex data string into multiple pieces of frame data, and an error checking means (311, 312, 313, 334) configured to perform error detection processing or error detection/correction processing in accordance with the setting processing by the error setting means, on each of the multiple data that result from the composition, wherein at least one of the transmitting side and the receiving side includes a processing circuit (45, 86; 91-94) configured to perform at least one type of processing operation among I/O control processing, sensor information fetching processing, communication protocol conversion processing, image input processing that fetches an output of an image element, and communication processing by a slave on a control network, wherein the processing circuit of the transmission side is configured to function as the multiplexing means and/or the processing circuit of the receiving side is configured to function as the restoration means wherein the multiple data include a detection signal that is output from a sensor element and an encoder signal that is output from an encoder which detects displacement of the electromagnetic motor, characterised in that the receiving side includes notifying means configured to notify a drive control section that controls the electromagnetic motor according to the encoder signal, after an activation delay time, which is a delay time set to start from a point in time when the multiplex means and the restoration means are activated, has elapsed, and wherein the drive control section, as a result of this notifying, activates an amplification section that controls the electromagnetic motor.