The XSYNC board for the NEXUS was designed for connecting to ex­ter­nal studio systems and devices. It provides two inputs used for syn­chro­nising the NEXUS system remotely: video and word clock. The syn­chro­nising input is selected using the NEXUS control program. External video signals are input via a standard BNC port. It is iso­lated galvanically and unbalanced (as specified by the format). The video input handles a number of formats: It accepts not only com­pos­ite and component video but also the new HD formats, including bi-le­vel and tri-level syncs, as the sync source. The XSYNC automatically detects the input format, so manual selection is unnecessary. It in­cor­po­rates a composite filter enabled selectively for suppressing analogue in­ter­fer­ence (noise, voltage peaks). External word clock signals are input via a standard BNC port. It is isolated galvanically and balanced. The port accepts TTL sig­nals. The nominal input impedance of 75 ohm can be changed to approx. 500 ohm. This allows for connection of multiple destinations to a single source.