What is the advantage of having a Doubly Bus Terminated Topology segment VS Free Topology in a LON FTT 10A setup?

Issue

What is the advantage of having a Doubly Bus Terminated Topology segment VS Free Topology in a LON FTT 10A setup?

Product Line

Andover Continuum

Environment

  • CX9900
  • CX9680
  • LON IOU Modules

Cause

Unknown

Resolution

The advantage is bus distance, with the doubly terminated bus you can have a bus length of up to 2700 meters (depending on type of cable used), with the free topology the maximum would be 500 meters. (see page 22 in the Continuum I/O Reference document).

The disadvantage is the Doubly Bus Terminated method is that it does not allow free topology, nodes must wired in a bus topology (just like in the LON RS-485 485) to limit electrical reflections.