DMX is a serial protocol, digital, unidirectional, lighting control system. It is reliable but subject to interference which makes it unsuitable for hazardous effects (pyrotechnics). Like most digital cables, the signal quality degrades over long distances. Repeaters can be used to increase the quality or the signal can be split with the equivalent ethernet switches. Devices are daisy chained together in a single cable and terminated with a special plug; a single DMX master is used as a control, every other device is known as a slave.