hysteresis value is common to Fault, Low and High setpoint values. The hysteresis value may be used to prevent
too frequent operation of the relay when the measured value is rising and falling around setpoint value.
The hysteresis setting operates as follows: For the ascending alarms, once the alarm is activated the input must fall
below the setpoint value minus the hysteresis value to reset the alarm. e.g. if
AL3 High
is to
50.0
and
AL3
HYSt
is set to
3.0
then the channel 4 alarm will activate once the display value goes to
50.0
or above and will
reset when the display value goes below
47.0
i.e. at
46.9
or below.
For the descending alarms, once the alarm is activated the input must rise above the setpoint value plus the hysteresis
value to reset the alarm. e.g. if
AL2 High
is to
0.0
and
AL2 HYSt
is set to
10.0
then the channel 5 alarm will
activate when the display value falls below
0.0
and will reset when the display value goes above
10.0
i.e at
10.1
or above. The hysteresis units are expressed in displayed engineering units.
5.4
Alarm relay trip time
Section:
AL 1
to
AL 8
Display:
triP
Range:
0
to
6553.5
secs
Default Value:
0.0
Default Access Level
3
Function number
4040
to
4047
Displays and sets the alarm trip time in seconds. The trip time is common for both alarm high and low setpoint
values. The trip time provides a time delay before the alarm relay will activate when an alarm condition is present.
The alarm condition must be present continuously for the whole trip time period before the alarm will activate. If
the input moves out of alarm condition during this period the timer will reset and the full time delay will be restored.
This trip time delay is useful for preventing an alarm trip due to short non critical deviations from setpoint. The trip
time is selectable over
0.0
to
6553.5
seconds.
To set the trip time value go to the
triP
function, press
F
and when you see a digit of the value flash use the
^
or
v
push buttons to set the required value then press
F
to accept this selection.
Example: If
triP
is set to
5.0
seconds then the display must indicate an alarm value for a full 5 seconds before
the relay will activate.
5.5
Alarm relay reset time
Section:
AL 1
to
AL 8
Display:
RSt
Range:
0
to
6553.5
secs
Default Value:
0.0
Default Access Level
3
Function number
4050
to
4057
Displays and sets the alarm reset delay time in seconds. The reset time is common for both alarm high and low
setpoint values. With the alarm condition is removed the alarm relay will stay in its alarm condition for the time
selected as the reset time. If the input moves back into alarm condition during this period the timer will reset and
the full time delay will be restored. The reset time is selectable over
0.0
to
6553.5
seconds.
To set the reset time value go to the
RSt
function, press
F
and when you see a digit of the value flash use the
^
or
v
push buttons to set the required value then press
F
to accept this selection.
Example: If
RSt
is set to
10.0
seconds then the resetting of alarm relay will be delayed by 10 seconds.
32 of
LD5RSMAN-2.0-0
