ABB Symphony Harmony Series, Instruction, Page: 160 / 402

Analog Output
WBPEEUI240751C0 4 - 5
module so that only one I/O module is driving the outputs at a
time (Fig.
4-8 ). A short across an output of one I/O module
due to an I/O block fault will not affect the output of the other
I/O module. An open in the output channel circuit of the base
will not allow either I/O module to control the output.
NOTE: Normal failover time for the AOT-150 block is less than 100 millisec-
onds. Under rare conditions, the output channels could be affected by a failover
for up to 200 milliseconds.
Figure 4-2. AIN-120 Block - Current Mode (IFP or LFP Powered)
T 0323 2A
+
+
+
+
+
+ 2 4 V
15 0 τ
2 50
τ
IFP /LF P
R E F 1
R E F 1
R E F 2
R E F 2
C H 1
C H 1
•
•
•
•
•
•
C H 16
C H 16
M U X
M U X
R E D U N DA N T
A IN -1 2 0 B A S E A IN -1 2 0 M O D U L E
A IN -1 2 0 M O D U L E
R E D U N DA N C Y LIN K
R E D U N DA N C Y LIN K
– –
–
–
–
IF C /L FC
A M P
A M P
A /D
A /D
A
A
A
B
B
B
H N E T
C P U
A N D
H N E T
IN T E R FAC E
C P U
A N D
H N E T
IN T E R FAC E
4 -2 0 m A
L O O P