Installation 
 
1 
Do not run the communications lines in the same conduit as AC power. 
D–
D+
COMMUNICATION MASTER
D+ (B)
SHLD D– (A)
120 OHMS
TO OTHER 
COMMUNICATION 
CONTROLLERS
D+D–
120 OHMS ON LAST LEG
16 SHLD
 
17 D+ (B) 
18 D– (A)
 
Connect shield 
to ground at one 
end only. 
SHLD
2 
Use shielded twisted pair cables (Belden 9271 Twinax or equivalent). 
2 
1 
 
Figure 2-15 RS-422/485 Communications Option Connections 
 
1
Do not run the communications lines in the same conduit as AC 
power.  Correct connections may require the use of an Ethernet 
cross-over cable.
COMMUNICATION MASTER 
OR SWITCH
RXD+SHLD
16 RXD-
17 TXD+
18 TXD-
14 SHLD
15 RXD+
RXD-
TXD+ TXD-
1
2
Use Shielded twisted-pair, Category 5 (STP CAT5) Ethernet cable.
2
3
Use Switch rather than Hub to maximize performance.
3
1
Do not run the communications lines in the same conduit as AC 
power.  Correct connections may require the use of an Ethernet 
cross-over cable.
COMMUNICATION MASTER 
OR SWITCH
TXD–SHLD
16 RXD
–
17 TXD +
18 TXD
–
14 SHLD
15 RXD +
TXD+
RXD–
RXD
+
1
2
Use Shielded twisted-pair, Category 5 (STP CAT5) Ethernet cable.
2
3
Use Switch rather than Hub to maximize performance.
3
3
1
Do not run the communications lines in the same conduit as AC 
power.  Correct connections may require the use of an Ethernet 
cross-over cable.
COMMUNICATION MASTER 
OR SWITCH
RXD+SHLD
16 RXD-
17 TXD+
18 TXD-
14 SHLD
15 RXD+
RXD-
TXD+ TXD-
1
2
Use Shielded twisted-pair, Category 5 (STP CAT5) Ethernet cable.
2
3
Use Switch rather than Hub to maximize performance.
3
3
1
Do not run the communications lines in the same conduit as AC 
power.  Correct connections may require the use of an Ethernet 
cross-over cable.
COMMUNICATION MASTER 
OR SWITCH
TXD–SHLD
16 RXD
–
17 TXD +
18 TXD
–
14 SHLD
15 RXD +
TXD+
RXD–
RXD
+
1
2
Use Shielded twisted-pair, Category 5 (STP CAT5) Ethernet cable.
2
3
Use Switch rather than Hub to maximize performance.
3
333
 
Figure 2-16 Ethernet Communications Option Connections 
Figure 2-16 and Table 2-7 shows how to connect a UDC to a MDI Compliant Hub or 
Switch utilizing a straight-through cable or for connecting a UDC to a PC utilizing a 
crossover cable. 
12/04  UDC3200 Universal Digital Controller Product Manual  33