ABB SM1000 User Manual page 58

...4 CONFIGURATION
...4.6.4 Alarm Configuration
Trip Point
Process
Variable
High Annunciate Alarm Action
Deviation exceeded –
high rate alarm
becomes active, low
rate alarm becomes
inactive, new period starts
Deviation Abt exceeded –
low rate alarm becomes
active, new period starts
Deviation
Deviation
High Rate Alarm
Period
Alarm On
Alarm Off
Low Rate Alarm
Alarm On
Alarm Off
56
Hysteresis
Alarm On
Alarm Off
Alarm acknowledged
by operator
Fig. 4.14 High/Low Annunciate Alarms
Fig. 4.15 Fast/Slow Rate Alarms
Process
Variable
Trip Point
Alarm On
Alarm acknowledged
Low Annunciate Alarm Action
Deviation within limits
at end of time period –
high rate alarm
becomes inactive, low
rate alarm becomes
active
Deviation exceeded –
high rate alarm becomes
active, low rate alarm
becomes inactive,
new period starts
Hysteresis
Alarm Off
by operator
Deviation within limits
at end of time period –
alarm becomes
inactive