Abstract: A device arranged to connect to a serial port and to use an electromagnetic link to replicate a serial connection thereto, the device comprising a link-processing module arranged to establish the electromagnetic link and at least one switching device capable of being switched from at least a first configuration to a second configuration and the link-processing module being further arranged to monitor at least one line of the serial port and the switching device being arranged to connect the or each monitored line to the link-processing module in a first and second configurations; the link-processing module being further arranged to send a command packet across the electromagnetic link if a change is detected in the at least one monitored line; and upon receipt of a command packet from the electromagnetic link to make a change to a pin of the serial port to which the device is connected thereby replicating a change of line represented by the command packet received thereby.