Garmin G3X Installation Manual page 40

Daisy-chained LRUs (LRUs not at the extreme ends of the CAN bus) connect to the CAN backbone
through short "stub" or "node" connections (Figure 2-7). The length of each node connection should be
kept as short as possible, and should not exceed 0.3 meters (1 foot). The best way to connect devices
between the ends of the CAN bus while maintaining short stub node lengths is to splice the connections as
close to the device as practical
practical.
Multiple devices must not connect to the CAN bus backbone at the same point. Rather than splicing two or
more stub node connections together, the CAN bus should instead be daisy chained from one device to the
next (Figure 2-7).
LRU
The layout of the CAN bus must be a single linear backbone with exactly two distinct end points
(Figure 2-8). Other layouts such as "star" or "Y" arrangements must be avoided. Similarly, hub devices
must not be used with the G3X CAN bus. (Figure 2-9)
LRU
LINEAR CAN BACKBONE, DAISY-CHAINED CONNECTIONS WITH SHORT STUB
NODE LENGTHS. MULTIPLE LRUs ARE NOT CONNECTED TO BACKBONE AT
THE SAME LOCATION.
LRU
LRU
LRU
AVOID "T" OR "Y" SHAPE
190-01115-01
Rev. AA
(Section 22.3.8). Unshielded wire sections should be kept as short as
LRU
Max. node length
0.3 meter (1 ft)
Figure 2-7 Node Connections
LRU
LRU
Figure 2-8 Correct CAN Wiring Example
LRU
LRU
AVOID STAR SHAPE
Figure 2-9 Incorrect CAN Wiring Examples
G3X/G3X Touch Installation Manual - Installation Preparation
LRU
LRU
LRU
LRU LRU
LRU LRU
DO NOT USE THIRD-PARTY
HUB DEVICES
LRU
LRU
LRU
HUB
DEVICE
LRU
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