5
vacon • 54
Control unit
Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/
5.4.1
Modbus RTU protocol
VACON
®
20 X drive is equipped with Modbus support as standard. The AC drive can be connected
to fieldbus through RS485. The connection for RS485 is on the standard I/O (terminals A and B). See
Figure 40.
Figure 40. Position of the RS485 terminals on the I/O standard terminal connector(MU2 control
unit example).
Table 25.
Connections and
communications
Interface
RS-485
Data transfer method
RS-485 MS/TP, half-duplex
Transfer cable
STP (shielded twisted pair), type
Belden 9841 or similar
Connector
2.5 mm
2
Electrical isolation
Functional
Modbus RTU
As described in “Modicon Modbus
Protocol Reference Guide”
Baud rate
300, 600, 1200, 2400, 4800, 9600,
19200, 38400 and 57600 baud
Addresses
1 to 247