Operation When Alarms Have Occurred - Mitsubishi Electric F930GOT-BWD Operation Manual

Graphic Operation Terminal GOT-F900
12.3.1

Operation when alarms have occurred

The figure below shows the outline of operation performed when alarms have occurred.
When a bit device assigned as an alarm device turns ON (OFF à ON), the GOT recognizes
that an alarm has occurred.
When two or more alarms have occurred, the GOT recognizes them one by one in turn.
Screen mode
Alarm 0
When many alarms have
occurred, corresponding
alarm messages are
displayed in the
ascending
order of device No.
Instead of an alarm
message, a specified
screen can be displayed.
Alarm mode
DISPLAY
STATUS
screen
Alarm 0
Alarm 3
• The ON/OFF status of alarm devices are read every time communication is performed
(every 300 to 400 ms) between the GOT and the PLC when FX-PCS-DU/WIN-E is used or
at the time interval (variable within the range of 600 to 100 ms) set by "Monitor Cycle" in
"Alarm History Common Setting" when GT Designer is used.
• Inside the GOT, alarm messages are displayed (overlaying on the user screens) or a
specified screen is displayed in the screen mode, alarm devices are stored in the history
and their frequencies are counted in the alarm mode in accordance with the contents set
preliminarily in the screen creation software.
• When two or more alarms have occurred, they are sorted in the ascending order of alarm
device No. in the alarm list and stored in alarm history in the order of occurrence.
When GT Designer is used, the alarm history can be stored in the order of occurrence (from
the oldest one) or in the reverse order of occurrence (from the latest one).
• In alarm history and alarm frequency, up to the following number of cases can be stored
respectively. They are stored even if the power is turned OFF.
Alarm history
Alarm frequency: Up to 32,767 cases
• If an alarm has occurred in any mode other than the screen mode, the occurrence history
and frequency are recorded. The display can be changed to a specified screen, and the
alarm can be output to a printer. (However, the alarm message does not overlay the base
screen displayed at that time.)
GOT
Alarm Device
message
0
1
2
3
254 n+254
255 n+255
ALARM
ALARM
FREQUENC
HISTORY
screen
screen
Alarm 0 Alarm 01
Alarm 3 Alarm 10
Alarm 20
: Up to 1,000 cases
If 1,001 or more alarms have occurred, the record is updated while
excessive alarms are deleted from the oldest one. (When GT Designer is
used, it can be set so that excessive alarms are deleted from the latest
one.)
If more alarms have occurred, 32,767 cases remain stored.
No.
n
n+1
n+2
n+3
The GOT monitors bit
devices in the PLC, and
recognizes that alarms have
occurred when they turn ON.
(Communication is performed
every 300 to 400 ms.)
Y
Output to the printer
(Alarm devices and alarm
messages are printed.)
Alarm Mode 12
PLC
ON/OFF Device
status No.
ON n
OFF n+1
OFF n+2
ON n+3
OFF n+254
OFF n+255
Up to 256 consecutive
alarm devices
Sequence program
n
n+255
12-8