P
P
E
E
S
S
1
1
9
9
0
0
0
0
G
G
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i
G
G
S
S
M
M
R
R
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p
p
e
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a
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r
PES1900NR Operations Manual
Chapter 7. Connecting External Alarms — 109
Figure 90 shows the critical alarm summary output relay, which is controlling an external, dual-color
(green/red) LED. Normally, the relay is open, and the green LED is biased on. When an alarm
occurs, the relay closes, and the LED turns red.
Figure 90 Critical Alarm Summary Relay, controlling an external LED