Alarm Type; Time Hysteresis - ABB COMMANDER 1900 Series Programming Manual

...3 BASIC CONFIGURATION LEVEL
...3.4 Set Up Alarms
tYPE
S–rAtE
F–rAtE
LO–dEV
HI–dEV
LO–OUt
HI–OUt
LO–PrC
HI–PrC
OFF
SELECt
OFF
trIP
––––––
HYSt
––––––
SELECt
t–HYSt
––––––
14

Alarm Type

Select the alarm type required for the alarm selected.
S–rtE – slow rate (rate of change of process variable)
F–rtE – fast rate (rate of change of process variable)
LO–dEV
– low deviation
HI–dEV – high deviation
LO–OUt – low output
HI–OUt
– high output
LO–PrC – low process
HI–PrC – high process
OFF – alarm off
Trip Level
Set the trip value required for the alarm selected.
The following are displayed in engineering units:
HPrC , LPrC , HI–dEV
The following are displayed as percentage (0.0 to 100.0%):
HI–OUt and LO–OUt
The following are displayed as a percentage of the engineering span (engineering range high –
engineering range low) per hour between ±0.5 and ±500%:
.
FrtE SrtE
and
Hysteresis
Hysteresis is operational when the alarm is active.
Set the hysteresis value required for high/low process or high/low deviation in engineering units
(within the engineering range) or in 0.1% increments for fast/slow rate and high/low output
alarms. The alarm is activated at the trip level but is only turned off after the alarm variable has
moved into the safe region by an amount equal to the hysteresis value. For rate alarms this
setting is a percentage of the trip rate – see

Time Hysteresis

Set the time hysteresis value required between 0 and 9999 seconds.
Note. The alarm condition must be present continually for the time set, before the alarm
becomes active. If a hysteresis level is also set, the alarm condition remains active until the
process variable moves outside the hysteresis band. When the alarm condition no longer exists
the alarm becomes inactive, i.e. time hysteresis does not affect turning off of alarm states.
Return to frame.
Select Alarm
Only displayed on Controller faceplate
and LO–dEV .
.
FrtE and SrtE in previous frame.