3 Mechanical and Electrical Installation NICE3000
new
User Manual
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The following gures show the common bus structures.
a. Hand-in-hand connection structure
Figure 3-27 Hand-in-hand connection structure
Host 1 Node 2 Node 3 Node 4 Node N
RS485 bus
b. Branch connection structure
Figure 3-28 Branch connection structure
Host 1 Node 2 Node 3 Node 4 Node N
RS485 bus
< 3 m
< 3 m
< 3 m
< 3 m
< 3 m
c. Wrong structure: star connection structure
Figure 3-29 Star connection structure (wrong)
Host 1
Node 2
Node 4
Node 7
Node 5
Node 6
Node 3
4. EMC precautions
● Use the twisted pair as the RS485 communication cable.
● Separate the RS485 bus from other interfering cables during cabling.