Installation
12/00 UDC3300 Basic Model: DC33XB User Manual 15
Communications Option
The Communications option is available for RS422/485/ASCII or Modbus (Model
DC330X-XX-1XX or DC330X-XX-5XX)—refer to Figure 2-15.
Figure 2-15 RS422/485/ASCII or Modbus Communications Option Connections
13
14
15
16
17
Master
TX+
SHD
TX–
RX+
RX–
Do not mix half and
full duplex wiring.
Do not run these lines in
the same conduit as AC
power
CAUTION
13
14
15
Master
TX–/RX–
SHD
TX+/RX+
ASCII or MODBUS
RS422/485
HALF DUPLEX
To Other
Communication
Instruments
(maximum 31)
SHD
TX+/RX+
TX–/RX–
ASCII
RS422/485
FULL DUPLEX
RX+
SHD
RX–
TX+
TX–
120 Ohm
Resistor
To Other
Communication
Instruments
(maximum 31)
120 Ohm Resistor
on Last Leg
120 Ohm
Resistor
120 Ohm
Resistor
120 Ohm Resistor
on Last Leg
1
1
1
Use shielded twisted pair
cables (Belden 9271
Twinax or equivalent)