ABB CM30 User Manual page 50

ControlMaster CM30 and CM50
Universal process controllers,
...Process Alarm
Alarm 1 (8)
Type
Tag
Source
Trip
Hysteresis
Time Hysteresis
Display Enable
Acknowledge Source
Enable Source
48
1 1
/ and / DIN
4 2
Alarm types comprise: High Process, Low Process, High Latch, Low Latch.
The alarm Tag is displayed as a diagnostic message and appears in the Diagnostic
Status Bar and the Diagnostic view in the Operator Level.
The analog source – see Appendix A, page 79 for description of sources.
Alarm trip level in engineering units.
Hysteresis trip level in engineering units. Activated at the alarm trip level but deactivated
only when the process variable has moved into the safe region by an amount equal to
the hysteresis value – see Process Alarm examples on page 47.
If an alarm trip value is exceeded, the alarm does not become active until the Time
Hysteresis value has expired. If the signal goes out of the alarm condition before the
Time Hysteresis has expired, the hysteresis timer is reset.
Enables an alarm to be used for control purposes without it appearing as an active
alarm state in the Operator level or Diagnostic views.
The source required to acknowledge all active
alarms. Acknowledge occurs on rising edge of the
digital signal – see Appendix A, page 79 for
description of sources.
The source required to enable alarms. If the source is None, alarms are always enabled
– see see Appendix A, page 79 for description of sources.
7 Advanced Level
Acknowledge
IM/CM/ED–EN Rev. B