ABB Symphony Harmony Series - Digital Output

Digital Output
WBPEEUI240751C0 4 - 9
Digital Output
For digital output capable blocks, channels are directly wired
in parallel to both I/O modules (Figs. 4-9 through 4-12). A
short across an output of one I/O module due to an I/O block
fault will not allow the output to switch off. There are no
detectable channel failures for the digital outputs of DIO-400
and DOT-100 blocks.
The DOT-120 block has readback circuitry to monitor actual
outputs. If there is a difference between the actual output and
the read back output, the channel will be marked as suspect.
For the DOT-120 block, failover will occur if the primary I/O
module has an output stuck closed, but the backup will be
unable to correct this condition.
Figure 4-6. AIN-220 Block - Current Mode (RFP Powered)
T03242A
REF1
REF1
REF16
REF16
1
1
16
16
CH 1
CH 1
CH 16
CH 16
•
•
•
•
•
•
•
•
•
•
•
•
AIN-220 MODULE
AIN-220 MODULE
REDUNDANCY LINK
REDUNDANCY LINK
AMP
AMP
AMP
AMP
A/D
A/D
A/D
A/D
OPTO-
COUPLER
OPTO-
COUPLER
OPTO-
COUPLER
OPTO-
COUPLER
A
A
A
B
B
B
HNET
CPU
AND
HNET
IN T E R FACE
CPU
AND
HNET
IN T E R FACE
+
+
+
+
REDUNDANT
AIN-220 BASE
–
–
–
–
+
+24 V
–
+24 V
4-20 mA
LOOP