
80224_MHW_650 L - 1250 L_07-2018_ENG - 47
4.6.5. PWON.E - Disabling the alarm at power-on
Acronym
Scrolling message
Submenu
Attributes
PWON.E
DISABLE AT SWITCH ON
ALARM
R W
The parameter shows and sets the behavior of the alarm (being configured) when the indicator is powered on.
If the parameter is “OFF,” the alarm will trip when the indicator is powered on if the process variable exceeds the alarm
setpoint limits.
If the parameter is “On,” the alarm will not trip until the alarm limit value is reached at least once after the indicator is
powered on.
The parameter only appears for ALARM=2, ALARM=3 and ALARM=4.
Only OFF for Alarm 1
ATTENTION! The setpoint can be reached in increment or in decrement, or it may never be reached. Therefore, with “On”
the alarm might never trip even if the value of the process variable exceeds the alarm setpoint limits.
Example – Minimum, inverse and absolute alarm
When the system is off, the process variable equals room temperature (20 °C). The alarm setpoint is set at 150°C ± 10°C.
The indicator powers on with the system.
So with “OFF” the alarm trips as soon as the indicator is powered on because the temperature of the process variable
exceeds the alarm setpoint limits.
Instead, with “On” the alarm trips only after the temperature of 150°C is reached at least once for the process variable.
Unit of measurement:
-
Options:
OFF
= Alarm enabled at power-on
On
= Alarm disabled at power-on (until setpoint is reached)
4.6.6. LATCH - Set alarm latching
Acronym
Scrolling message
Submenu
Attributes
LATCH
MEMORY DEFINITION
ALARM
R W
The parameter shows and sets latching of the alarm being configured.
Latching maintains the active alarm state even after the alarm conditions are eliminated.
The alarm state can be removed by or reset by the digital input, serial input, or key.
Only On or ONnOF settable for ALARM=1
Unit of measurement
: -
Options:
OFF
= Alarm not latched (for Alarms 2...4 only)
On
= Alarm latched with status saved even after Power OFF
OnOF
= The alarm is saved with status deleted after Power OFF
4.6.7. HYSTE - Hysteresis
Acronym
Scrolling message
Submenu
Attributes
HYSTE
HYSTERESIS
ALARM
R W
The parameter shows and sets the hysteresis applied to the alarm setpoint value for the alarm being configured.
The parameter only appears for ALARM=2, ALARM=3 and ALARM=4
Unit of measurement
:
Scale points
Options
:
0...999
= For absolute (A.r.x = ABSLT) and symmetrical alarm (n.S.x = SYMMT)
-999...999
= For other types of alarms
4.6.8. DELAY - Alarm trip delay
Acronym
Scrolling message
Submenu
Attributes
DELAY
DELAY OF ACTIVATION
ALARM
R W
4. CONFIGURATION