ABB Symphony Harmony Series, Instruction, Page: 161 / 402

4 - 6 WBPEEUI240751C0
Analog Output
Analog output channel failures detectable by the primary I/O
module that cause a failover to the backup I/O module
include:
•
Failed output driver.
•
Failed output amplifier.
•
Failed output sample and hold circuit.
•
Failed readback circuit.
- Amplifier failure.
Figure 4-3. AIN-120 Block - Current Mode (RFP Powered)
T 0324 0A
+
+
+
+
+
+24 V
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 D A N T
A IN -120 B A S E A IN -120 M O D U LE
A IN -120 M O D U LE
R E D U N DA N C Y LIN K
R E D U N DA N C Y LIN K
– –
–
–
–
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
+24 V
4-20 m A
LO O P
250
τ