M-system 47DV, Operating Manual

Page: 21 / 34

47DV
P. 21 / 34 EM-9501-B Rev.6
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FUNCTIONS, TERMINOLOGY
• Alarm action basics
Alarm trip operates in relation to the display value.
Alarm indicators, except for P indicator, do not turn on until all parameters (display value, deadband, ON delay time
elapsed) of the setpoint become true. Display color is switched accordingly.
P indicators normally turns on when no other indicators are on. It turns off during ‘no measuring’ status.
P indicator, as an exception, remains on during ON/OFF delay time even when another alarm indicator may be on as shown
in the example below.
• Alarm output pattern
Normal and Zone patterns are selectable.
In ‘Normal’ setting, alarm trips according to the setpoint and the trip action (direction) setting.
In ‘Zone’ setting, alarm trips and resets between each setpoint. Alarm trip action setting is disregarded with zone alarm.
If a setpoint is set to invalid, no output is provided for the zones adjoining the setpoint (e.g. P and L are not provided with L
set to invalid.)
HH setpoint
H setpoint
L setpoint
LL setpoint
/ High trip
/ High trip
/ Low trip
/ Low trip
LL L P H HH
ON
ON OFF
OFF
OFF
ON
ON OFF
OFF
OFF
ON
HH setpoint
[Example] Typical LL / L / H / HH trip setting [Example] All trip points set to High setting
H setpoint
L setpoint
LL setpoint
/ High trip
/ High trip
/ High trip
/ High trip
P LL L H HH
ON OFF
OFF
OFF
OFF
ON OFF
ON
ON
ON
HH setpoint
H setpoint
L setpoint
LL setpoint
LL L P H HH
ON OFF
ON
OFF
OFF
OFF
ON
ON
OFF
OFF
OFF
ON OFF
LL L P H HH
ON
OFF
No output for
the zones adjoining
the invalid setpoint.
ON
OFF
OFF
OFF
ON OFF
OFF
HH setpoint / High trip
H setpoint / High trip
L setpoint / Invalid
LL setpoint / Low trip
[Example] Typical zone setting
[Example] Zone setting with invalid setpoint at L
H setpoint / High trip
A
Alarm
confirmed
Display reading
H indicator
P indicator
ON ON OFF ON ON ON ON
OFF OFF ON ON OFF OFF OFF
tH
B C
tL tH
Time
D
ON delay
trigger point
H setpoint / High trip, tH = H ON delay time, tL = H OFF delay time
A
:
B :
C :
D
:
ON delay time is triggered when the display reading exceeds the H setpoint.
Alarm is handled as ‘Non-confirmed’ during ON delay or OFF delay time period.
P indicator always turns on during this non-confirmed time period.
H indicator turns on after the ON delay time tH has elapsed.
H indicator turns off after the OFF delay time tL has elapsed.
ON delay time is triggered again but is reset within the ON delay time period.
H indicator remains off.
[Example]
High alarm trip and indicators action with ON/OFF time delay