Inovance AM600-4AD - Page 87

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Introduction
485+
485-
CGND
485+
485-
RS485 bus
CGND
termination
resistor
AM600
120Ω
termination
resistor
120Ω
485+
485- CGND
485+
485- CGND
Master station
Slave station 1
Set the termination
resistor through
switches 3 and 4 or 5
and 6 of the main
module
Slave station N
DIP switch
DIP switch
Used to set the
termination
resistor on the
network terminal
Figure 5-28 RS485 communication connection
■
Multi-node connection
When the number of nodes is large
,
the RS485 bus uses the daisy chain connection mode. If branch
cables need to be connected
,
you are advised to keep the branch cable length between the bus and the
node shorter than 3 m. Do not use the star-shaped connection mode. The following 󶍾gure shows the
common bus structure:
.BTUFS
TUBUJPO
4MBWF
TUBUJPO

4MBWF
TUBUJPO

4MBWF
TUBUJPO

4MBWF
TUBJUPO
/
34CVT

3FDPNNFOEFE
Figure 5-29 Daisy chain connection structure
.BTUFS
TUBUJPO
4MBWF
TUBUJPO

4MBWF
TUBUJPO

4MBWF
TUBUJPO

4MBWF
TUBUJPO
/
34CVT
N
N
N

3FDPNNFOEFE

Figure 5-30 Keep the branch cable length shorter than 3 m when branch cables are used