Engineering Documentation

Table Of Contents

Chapter 2 – Network Electrical Systems

LONWORKS FLN Communications Wiring

125

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61 | 231

Nodes per Subnet/Network

Any device that contains a Neuron ID (and therefore a unique address) is counted as

a node. Devices such as repeaters and network terminators do not have addresses

and thus are not counted as nodes.

Electrical Loads

The number of electrical LonWorks bus loads allowed per segment is 64. All devices,

with the exception of the network terminator, count as one electrical load. Networks

with more than 60 nodes should use a repeater. Two-port (P/N 587-450) and three-

port (P/N 587-455) repeaters are available.

Segment

A LonWorks FLN consists of 1, 2, or 3 network segments. A segment is defined as a

part of the physical network containing nodes that can communicate with each other

without requiring intervention from an intermediate device, such as a repeater.

Wiring Between Buildings

Use a LonWorks repeater for segments that run between buildings to protect the

network against lightning or other high voltage spikes. Additional communication

grade surge suppressors should be used as well.

Repeater Depth

Repeater depth refers to the number of repeaters that can be connected in series to

any given segment. The APOGEE with LonWorks system repeater depth is 1, which

means that only one end of a segment can be connected to a repeater. This allows

you to extend the channel wire length by either one or two segments, depending on

which repeater type you use. Two-port (P/N 587-450) and three-port (P/N 587-455)

repeaters are available.

Network Speeds

The LonWorks FLN operates at 78K bps.

Conduit Sharing

The LON FLN cable can be run in the same conduit or raceway with 24 Vac power

and AI, DI, and AO circuits. For more information on conduit sharing, see Conduit

Sharing—Class 1/Class 2 Separations [➙ 14] in this document.

Wire Lengths

The maximum total wire length per segment is calculated by summing the lengths of

all network wire on a segment. The maximum node-to-node length is the maximum

distance allowed between adjacent nodes on the same segment. See Figure

Determining Network Length—Example.

Two-port and three-port repeaters can extend the subnet by providing one or two

additional segments, with wire lengths as defined in Table LonWorks FLN Wiring

Specifications [➙ 60].