Mitsubishi Electric MELSEC FX2N-2LC, Руководство пользователя

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Alarm 6
6-1
6
6. Alarm
The FX
2N
-2LC is equipped with 14 types of alarms. Among them, up to 4 types can be used in
accordance with the application.
The alarm types to be used can be selected using buffer memories. The result of each alarm
is written to BFM #1 and BFM #2, and can be read in the PLC main unit.
When the measured value (PV) is near the alarm set value of an used alarm type, the alarm
status and the non-alarm status may be repeated by fluctuation in inputs. In order to cope with
such a case, the alarm dead zone can be set to prevent repeating of the alarm status and the
non-alarm status. (The dead zone of alarms 1 to 4 can be set using BFM #76.)
Table 6.1:
Alarm
No.
Alarm type Description
Set
range
0 Alarm function OFF Alarm function is disabled. ---
1 Upper limit input value alarm
When measured value (PV) is more than alarm set
value, an alarm is issued. Input
range
2 Lower limit input value alarm
When measured value (PV) is less than alarm set
value, an alarm is issued. Input
range
3 Upper limit deviation alarm
When deviation (= Measured value (PV) - Set
value (SV)) is more than alarm set value, an alarm
is issued.
±Input
width
4 Lower limit deviation alarm
When deviation (= Measured value (PV) - Set
value (SV)) is less than alarm set value, an alarm
is issued.
±Input
width
5 Upper/lower limit deviation
When absolute deviation (=

Measured value (PV)
- Set value (SV)

) is more than alarm set value, an
alarm is issued.
+Input
width
6 Range alarm
When absolute deviation (=

Measured value (PV)
- Set value (SV)

) is less than alarm set value, an
alarm is issued.
+Input
width
7
Upper limit input value alarm
with wait
When measured value (PV) is more than alarm set
value, an alarm is issued. However, when power is
turned on, measured value is ignored.
Input
range
8
Lower limit input value alarm
with wait
When measured value (PV) is less than alarm set
value, an alarm is issued. However, when power is
turned on, measured value is ignored.
Input
range
9
Upper limit deviation value
alarm with wait
When deviation (= Measured value (PV) - Set
value (SV)) is more than alarm set value, an alarm
is issued. However, when power is turned on,
measured value is ignored.
±Input
width
10
Lower limit deviation value
alarm with wait
When deviation (= Measured value (PV) - Set
value (SV)) is less than alarm set value, an alarm
is issued. However, when power is turned on,
measured value ignored.
±Input
width
11
Upper/lower limit deviation
value alarm with wait
When absolute deviation (=

Measured value (PV)
- Set value (SV)

) is more than alarm set value, an
alarm is issued. However, when power is turned
on, measured value is ignored.
+Input
width
FX2N-2LC Temperature Control Block