Instruction Manual

Module Preparation, Wiring, and
Installation
Chapter 2
2-6
Figure 2.4
T ypical Point-to-point W iring for Up to Four 4-digit Thumbwheel Switches (Maintained
Switch Contact Mode)
Enable
SW4
8421 8421
C
D
E
F
G
H
I
B
A
AABB
LSDLMDUMDMSD
SW1
4–Digit
Digit Junction
8421
Field Wiring Arm
Module Inputs 7 6 5 4 3 2 1 0 ABCDEFGHI
Enable Lines
10365
2 3 4 6 5 7 8 9
10
11
12
13
14
15
16
17
18 1
Lines
G & H
E & F
C & D
SW3
SW2
8
Thumbwheel
Switch
(User Supplied)
Terminal Strip
(User Supplied)
1771–WF
8421
MSD UMD LMD LSD
MSD
MSD
UMD
UMD
LMD
LMD
LMD
LSD
LSD
421 8421 8421 8421