Bus Termination - BONFIGLIOLI Vectron ACTIVE Manual

4.2.3 Bus termination

Attention!
It is important to realize the correct termination. If not, no communication is possible
by the RS485 interface!
As an alternative the active bus termination is possible via corresponding circuit:
The active termination is only allowed once each branch. The bus termination via an
external circuit and via DIP switch at the same time is not allowed.
Take care for the ground wiring; this will protect the communication bus for a high
noise level.
For easy wiring the signal terminals A and B have parallel contacts.
Example of wiring with different CM-485 modules:
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The passive bus termination (connection of a termination resistor) is
required at the physically first and last client. It can be activated by the
DIP Switch S1 of the CM-232 and CM-485.
By default, the bus termination is set to OFF.
B A
GND
Master (PC)
termination ON
Modbus Instruction manual
Modbus Instruction manual
max. 1200 - 2400m
1 2 7 8 3
B A
9pin D-Sub
GND
Inverter 1
termination OFF
3 4 1 2 6
B A
7pin terminal
GND
Inverter (last)
termination ON
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