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Electronic Theatre Controls Inc

Lon Infrastructure for Architectural Systems

Lon is a data standard created by Echelon and used largely by ETC Architectural products to carry data and power to architectural outstations such as button stations, occupancy sensors and daylight sensors.

Lon is assigned different names depending on the system it is being used with:

  • Paradigm: LinkConnect
  • Legacy Unison: LinkPower
  • SmartLink: LinkConnect

NOTE: Echo does not use a Lon-based protocol. It uses a proprietary protocol named EchoConnect.

It is important to note that although the cabling is the same for all of these systems, the data carried is not the same - for example, connecting a SmartLink station to a Paradigm processor will not work!

Voltage Expectations

The voltage requirements also vary depending on the system:

  • Paradigm and Legacy Unison: ~ 42vdc
  • Echo: ~21vdc
  • SmartLink: ~ 42vdc
  • Note: AUX voltage for all systems is ~24vdc (except for Pre-CE Legacy Unison systems, which used ~12vdc for AUX)


Lon is a topology free cabling system, meaning that the cable can be split, starred, daisy chained or any combination of these. The total length of cabling must not exceed 1640ft (500m) without use of a repeater. With regards to Paradigm there can be no more than 1,313ft (400.2m) between any two communicating devices. With regards to Echo when using Belden 8471 or equal the last device on the longest run needs to be less than 1000ft (304.8m). When the Echo system is utilizing Cat5e wiring the distance from the power supply to the last device on the longest run needs to be less than 750ft (228.6m).

ETC recommends the use of Belden 8471 cable for Lon systems. It is very important to note that DMX cable, Cat5 cable and other types will not work for Paradigm and legacy Unison.  It is possible to use Cat5e cable in Echo, but it will limit your total bus length to 1000 ft. (304.8m).

ETC has compiled a cable cross database that includes tested possible substitutes and whether or not they are approved. If you want to use a cable that is not on that list, it will need to be checked and approved by our Applications Engineering team.

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