Mitsubishi Electric Melsec Q Series User Manual page 34

4 Functions
(3) How to reset Alarm flag
1) When Alarm flag is ON during the alarm occurrence or the self-retention (in the case of the
alarm reset method = "self-retention"), Alarm flag can be reset (turned OFF) using Alarm
reset request.
2) How to reset Alarm flag during alarm occurrence (example of the upper limit alarm
monitoring with the alarm 1)
(a) If the measured value that was set with the alarm 1 item exceeds the upper limit, Alarm 1
flag (XnA) will turn ON. At the same time, ALM1 LED flashes.
(b) By turning Alarm 1 reset request (YnA) to ON, Alarm 1 flag (XnA) will turn OFF. At this
time, ALM1 LED will remain flashing (because ALM1 LED is synchronized with the alarm
status, it will not turn off).
(c) Check that Alarm 1 flag (XnA) becomes OFF, and then set Alarm 1 reset request (YnA) to
OFF.
(d) If the measured value goes below the upper limit, ALM1 LED will turn off.
(e) After that, if the measured value exceeds the upper limit, Alarm 1 flag (XnA) will turn ON
again. At the same time, ALM1 LED flashes.
Alarm 1 flag (XnA)
Alarm 1 reset request (YnA)
Figure 4.2.4-5 Procedure for resetting Alarm 1 flag (alarm reset method = "auto-reset")
3) How to reset Alarm flag during self-retention (in the case the alarm reset method =
"self-retention" only)
Refer to the procedure described in (2) 1).
(4) Precautions during the alarm monitoring
1) When current demand time and electric power demand time are set to anytime except 0
second, current demand and electric power demand become lower than the actual values
(closer to 0) immediately after the power source ON and the CPU reset. When current
demand and electric power demand are being monitored for their lower limit, the alarm
occurrence flag may turn ON. Thus, to avoid this from happening, follow the procedure
below.
(a) Set the alarm monitoring target to "no monitoring" immediately after the power source ON
and the CPU reset.
(b) After passing for a 3-times longer period than the demand time, set the alarm monitoring
target again, and start the alarm monitoring.
Upper limit
Alarm delay time
Flashing
OFF
Alarm delay time
OFF
4 - 16
Flashing
QE81WH