User`s guide
Copyright © 2004 EIM COMPANY, INC. • 13840 PIKE ROAD • MISSOURI CITY, TX. 77489
Page 15
Controlinc 1746-C (Version 5.21) Network Master Users Guide (2004-11-18)
3.2. Field Network Cable Connection to the NIU
Refer to Figure 3-2 for terminals on the EIM
Network Interface Unit (NIU). The NIU is a dual port
RS232 to RS485 converter specifically designed for
ring networks.
Connect the twisted shielded pair cable of the field
network to NIU Terminals 1 (-), 2 (Shield), 3 (+) of
J1 of Port A.
The network shield must be connected to a good
earth ground at only one shield terminal point on the
NIU.
The network cabling should use recommended
cabling for an RS-485 network able to handle the
distance desired.
There should be little, if any, electrical noise on the
network for the entire length of the network.
3.3. Cable Connection Between the NIU and the Network Master
Refer to the “
Allen-Bradley SLC-500 BASIC User's Manual (1746-BAS & 1746-BAS-T) Publication
No. 1746-UM004A-US-P 2000”
for additional information on the pin-out of the male DB9 connections
used for network ports one and two.
Jumpers JW1 & JW2 must be set for RS-232 when connecting with EIM's Network Interface Unit (NIU)
P/N 84320 or a user-supplied modem.
Refer to Figure 3-2 for the pin-out of the DB-9 female connector.
J3
N
I
U
8
4
3
2
0
Network
Por t
+
sh
-
P
W
R
R
S
-
2
3
2
P
o
r
t
1
1
2
V
A
C
/
D
C
P
W
R
J
2
PWR
TxD
RxD
+
-
Shield
J1
1
SW1
DB-9 Female
Connector
(1746-C Side)
DB-9 Male
Connector
(NIU Side)
RS232 Cable
(#37121)
Chassis
RXD
TXD
Ground
Ground
TXD
RXD
Shield
2
3
5
1
2
3
7
Figure 3-2