5.9
Alarm relay normally open/closed
Section:
RL 1
to
RL 8
Display:
RLY
Range:
n.o
,
n.c
Default Value:
n.o
Default Access Level
4
Function number
4030
to
4037
Displays and sets the setpoint alarm relay x action to normally open (de-energised) or normally closed (energised),
when no alarm condition is present. Since the relay will always open when power is removed a normally closed
alarm is often used to provide a power failure alarm indication. To set the alarm relay for normally open or closed
go to the
RL1
to
RL8 RLY
function and use the
^
or
v
push buttons to set the required operation then press
F
to accept this selection. Example:
If set to
A1n.o
alarm relay 1 will be open circuit when the display is outside alarm condition and will be closed
(short circuit across COM and N/O terminals) when the display is in alarm condition.
5.10
Relay acknowledge
Section:
RL 1
to
RL 8
Display:
Ack
Range:
OFF
or
ON
Default Value:
OFF
Default Access Level
4
Function number
4320
to
4327
If an alarm has been set to latching operation it will not reset until the reading is outside its alarm condition and the
operator has acknowledged the alarm by pressing the
F
button (where fitted) or using a
P
button of remote input
to acknowledge the alarm. If the
Ack
is set to
ON
the operator can acknowledge the alarm whilst still in alarm
condition allowing the alarm to reset automatically when the reading moves outside the alarm condition.
5.11
Alarm relay Boolean logic operation
Section:
RL 1
to
RL 8
Display:
booI
Range:
Or
,
And
Default Value:
Or
Default Access Level
4
Function number
4310
to
4317
This function allows a Boolean logic AND (
And
) or OR (
Or
) function to be applied to alarms. If two or more
alarms use the same relay and that relay is set to operate as an OR operation then this effectively puts the alarms
in parallel. If two or more alarms use the same relay that relay is set to operate on an AND operation then this
effectively puts the alarms in series.
Examples: 1. If alarms 1, 2 and 3 all use relay 1 and relay 1 is set for
Or
operation then relay 1 will activate if the
display value for the selected channels for these alarms causes either alarm 1 or alarm 2 or alarm 3 to go into alarm
condition. i.e. relay 1 will activate if any of the alarms is in alarm condition.
2. If alarms 1, 2 and 3 all use relay 1 and relay 1 is set for
And
operation then relay 1 will activate if the display
value for the selected channels for these alarms causes alarm 1 and alarm 2 and alarm 3 to go into alarm condition.
i.e. all 3 alarms must be in alarm condition for relay 1 to activate.
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