Mitsubishi Electric Melsec Q Series User Manual page 141

6
FUNCTIONS
(b) In the case of load concentration (Trigger interval
[MES interface module]
[When loads are concentrated]
Job 1-1)
Trigger
conditions met
Job 1-2)
Trigger
conditions met
Job 3-3)
Trigger
conditions met
Time
The numbers 1) to 3) show the order in which trigger conditions of respective jobs are met.
Job 1 and 3 are assumed to access the same database.
(c) When loads are reduced (Trigger interval
[MES interface module]
[When loads are reduced]
Time
The numbers 1) to 3) show the order in which trigger conditions of respective jobs are met.
Job 1 and 3 are assumed to access the same database.
• Every time a trigger condition is met, tag data and trigger time are stored in
the trigger buffer.
• When action processing is not completed in time, up to 128 pieces of trigger
information are stored in the buffer.
Trigger buffer
Job 1-2) Trigger information (tag data, time)
Job 3-3) Trigger information (tag data, time)
Figure 6.6 In the case of load concentration
• The information in the trigger buffer are read out sequentially, causing actions
to be executed.
• Since the trigger buffer information that was used for action execution is
cleared, free space is reproduced, enabling new trigger buffering.
Trigger buffer
Figure 6.7 When loads are reduced
Processing time for action)
Sending
Job 1-1)
data
Action
execution
Database
Executes action of Job 1-1), and stores
trigger information of Job 1-2) and 3-3)
in the trigger buffer.
Time
Processing time for action)
Sending
Job 1-2)
data
Action
execution
Database
Job 3-3)
Action
execution
After completing the action of Job 1-1),
executes actions of Job 1-2) and 3-3)
in this order based on the trigger buffer
information.
Time
6.1 DB Interface Function
6.1.5 Trigger buffering function
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