RS-485 User's Manual MEH448d - Fuji Electric America

(3) Example of typical connection other than above (Multidrop connection using the RJ-45
connector)
The figure below shows a connecting example to the multi-drop circuit with RJ-45
connector. RJ-45 needs a multi-drop branch adaptor as an external device for relaying.
The adaptor for relaying is not necessary for the inverter with RJ-45 connector for function
expansion. Set the terminator insertion switch of the terminating inverter to ON. For the
terminator insertion switch ON/OFF switch, see "2.2.2 Cautions [2] About terminating
resistors."
Figure 2.3 Multidrop connection diagram (connection via the RJ-45 connector)
Converter: Not necessary if the host is equipped with RS-485 interface.
Branch adapter for multidrop: Useful when implementing 1:n multidrop configuration using a
cable with a RJ-45 connector.
Cable: Use a connection cable meeting the specification. (Refer to
2.1.4.)
- A power supply for the keypad is connected to the RJ-45 connector of the inverter
(via pins 1, 2, 7, and 8). When connecting the inverter with another device, do not use
the pins assigned to the power supply but use the signal pins (pins 4 and 5).
- When selecting additional devices to prevent the damage or malfunction of the
control PCB caused by external noises or eliminate the influence of common mode
noises, be sure to see section 2.2.3 "Devices for connection."
- Keep the total wiring length 500m max.
- For FRENIC-Mini, the RS-485 communications card (option) is necessary for
connection.
2-10
FRENIC-MEGA