Mitsubishi Electric MELIPC MI5000 Series User Manual page 114

Event history file
The event history file is saved to the system memory of this product.
File size
When the configured file size for the event history file is exceeded, the latest history is saved after deleting the oldest history.
The file size is calculated using the following formula.
• File header size + Event history management information size + Number of records×Size per event history record
The following points show the size of each element.
• File header size: 20 bytes
• Event history management information size: 12 bytes
• Size per event history record: 40 to 1,112 bytes
*1 Because there are events that span multiple records in the event history, the file size per record changes.
Conditions for collecting events
This product collects event history regardless of its operating status (stop error, etc.) However, this product may not be able to
collect event history under the following statuses.
• Major error
• Cable failure
Creation timing
Event history files are created at the following times.
• When the power of this product is turned OFF and ON or after a reset of this product (when no event history file exists /
after a change of event history settings)
• initialization
• At registration of event history (no event history file exists)
When a new event history file is created, the event that indicates a new file creation is saved.
Parameter reflection timing
Parameter application is enabled at the following times when the event history file settings were changed.
• Turning the power supply of this product OFF to ON or after a reset of this product
Event history loss
If the event are detected frequently, some events may be dropped. In this case, the event code (*HST LOSS*) which indicates
that the event is dropped is displayed.
If the power is turned OFF or a reset is performed during event history sampling, an event code (*HST LOSS*)
may be displayed under the following statuses.
• When the source is not displayed (source information unknown)
8 DIAGNOSTIC AND MAINTENANCE FUNCTIONS
112
8.4 Event History Function
*1