Analog Point-To-Point Communications Wiring; Abb Digital Field Bus And Hart Wiring - ABB STT04 Instruction Manual

DESCRIPTION AND OPERATION
+
S Y S T E M P O W E R
S U P P LY
–
C O M M U N IC AT IO N S A R E
N OT P O S S IB L E O N T H IS
S ID E O F 2 5 0-
Figure 2-1. Analog Point-to-Point Communications Wiring
S IG N A L W IR E S
+
P W R /
O U T P U T
–
F IE LD D E V IC E 1
Figure 2-2. ABB Digital Field Bus and HART Wiring
PHYSICAL OPERATION
2 - 2
S IG N A L W IR E S
2 50 Ω
– +
C O N T RO L L E R ,
R E C O R D E R O R
C O N T R O L S Y S T E M
C O M M U N IC AT IO N S A R E
P O S S IB L E O N T H IS S ID E
Ω Ω
R E S IS TO R O F 2 5 0 - R E S IS TO R
U P TO 1 M I. (1 .6 K M )
T E R M IN AT IO N
S T T
S T T
F IE LD B U S
U N IT I/O M O D U LE
+
P W R /
O U T P U T
–
F IE LD D E V IC E 8
+
P W R /
O U T P U T
–
F IE L D D E V IC E
T 01323B
M F P /M F C
T 0 132 4B