INVT Goodrive300-19 Series Operation Manual page 210

Goodrive300-19 series open loop vector inverter special for hosit
higher the baud rate is, the quicker the transmission speed is and the weaker the anti-interference is.
If the twisted pairs of 0.56mm (24AWG) is applied as the communication cables, the Max.
transmission distance is as below:
Baud rate
2400BPS
4800BPS
It is recommended to use shield cables and make the shield layer as the grounding wires during
RS485 remote communication.
In the cases with less devices and shorter distance, it is recommended to use 120Ω terminal resistor
as the performance will be weakened if the distance increase even though the network can perform
well without load resistor.
10.3.1.1 Single application
Figure 1 is the site Modbus connection figure of single inverter and PC. Generally, the computer does
not have RS485 interface, the RS232 or USB interface of the computer should be converted into
RS485 by converter. Connect the A terminal of RS485 to the 485+ terminal of the inverter and B to the
485- terminal. It is recommended to use the shield twisted pairs. When applying RS232-RS485
converter, if the RS232 interface of the computer is connected to the RS232 interface of the converter,
the wire length should be as short as possible within the length of 15m. It is recommended to connect
the RS232-RS485 converter to the computer directly. If using USB-RS485 converter, the wire should
be as short as possible, too.
Select a right interface to the upper computer (select the interface of RS232-RS485 converter, such
as COM1) after the wiring and set the basic parameters such as communication baud rate and digital
check bit to the same as the inverter.
Max. transmission
distance
1800m
1200m
Baud rate
9600BPS
19200BPS
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Communication protocol
Max. transmission
distance
800m
600m