BACnet Communication Accessory
CFW-11 | 8
2.1.4
Indications and Switches
TX LED: LED for the indication of data transmission by the
frequency inverter, in green color.
Termination resistor (S1): switch for enabling the termination
resistor, necessary for the RS485 interface. This resistor must be
enabled (position ON) only at the devices located at the extremes
of the main bus.
2.1.5
Connection with the RS485 Network
The following points must be observed for the connection of the frequency inverter using the RS485 interface:
It is recommended the use of a shielded cable with a twisted pair of wires.
It is also recommended that the cable has one more wire for the connection of the reference signal (GND).
In case the cable does not have the additional wire, then the GND signal must be left disconnected.
The cable must be laid separately (and far away if possible) from the power cables.
All the network devices must be properly grounded, preferably at the same ground connection. The cable
shield must also be grounded.
Enable the termination resistors only at two points, at the extremes of the main bus, even if there are
derivations from the bus.
2.2
ANYBUS-CC
The RS485 interface can also be made available by using the passive Anybus-CC kit available for RS485. Refer
to the Anybus-CC Communication Manual for information on this kit.
