INVT Goodrive350 Series Operation Manual page 313

Goodrive350 IP55 High-ingress Protection Series VFD
9.3.1.2 Application to multiple VFDs
In practical application to multiple VFDs, chrysanthemum connection and star connection are
commonly used.
According to the requirements of the RS485 industrial bus standards, all the devices need to
be connected in chrysanthemum mode with one 120 Ω terminal resistor on each end, as
shown in Figure 9-2. Figure 9-3 is the simplified wiring diagram, and Figure 9-4 is the practical
application diagram.
120Ω
1 #
A+
B-
Master
Figure 9-4 Practical application diagram of chrysanthemum connection
Shielded twisted pair
RS232-RS485
Converter
Max. length of the
GND
cable: 15 m
PC
Figure 9-5 shows the start connection diagram. When this connection mode is adopted, the
two devices that are farthest away from each other on the line must be connected with a
terminal resistor (the two devices are devices #1 and #15).
Figure 9-2 On-site chrysanthemum connection diagram
2 #
Figure 9-3 Simplified chrysanthemum connection diagram
A+ B-
1#
485 +
485-
Earth
INVT
VFD
Address 1
3 # 4 #
2# 3#
485+
485 -
Earth
INVT
VFD
Address 2
-295-
Communication protocol
120Ω
32 #
31#
120Ω
485 +
Terminal resistor
485-
Earth
INVT
VFD
Address N