Ethernet and the Future

Ethernet

The latest development is to send DMX data over Ethernet networks (as used for computers), though currently there are a number of competing products, and their use is less common. The most important difference to note from conventional DMX is that Ethernet has a star topology with separate links from each device to a switch/hub rather than being daisy chained. Care must be taken to ensure the standard rules for creating Ethernet networks must be obeyed (e.g. maximum cable lengths, cable quality, number or devices, hubs etc.).

Ethernet allows massive numbers of channels (many universes) to be sent over just a few wires, and allows devices to reply back their status. Currently the main use is for bulk transfer between two points (e.g. from a control desk to backstage), with distribution to individual fixtures relying on standard DMX, though in the future fixtures may be connected directly.

Remote Device Management (RDM)

RDM is an enhancement to DMX, and brings some of the same advantages as Ethernet; status responses, remote addressing/automatic discovery of connected devices. However, because it is so new, there currently are very few products that make use of it. If RDM is to be used in an installation then any splitters/mergers/buffers in the system must specifically support it.