Page History

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• Name
  • The name of the History Store.
• Enabled
  
  • Checkbox to enable/disable the History Store. Not selected by default.
• Type
  • The type of History Store.
  • Data stored in an In-Memory History Store will not be persisted across a module configuration change, module disable/enable, module restart or power loss. 
  • Data stored in a Disk-Backed History Store will persist across a module configuration change, module disable/enable, module restart or power loss.
• History Max Size
  • Maximum number of megabytes history can use before dropping the data
  • An In-Memory History store will use the Ignition Java Heap memory
• History Max Age
  
  • Maximum number of minutes to store history before dropping the data.
• Flush Quantity
  • The maximum number of tags to publish in a single message upon reestablishing communication.
• Flush Period
  • The period to wait in milliseconds between publishes acquisition and publishing of the historical data when flushing messages upon re-establishing communication
  • MQTT Transmission queries the history store and builds up a publish, and publishes it, and then delays by the Flush Period.
    The actual message publish frequency is not deterministic as the time to gather the publish from the history store can vary depending on the frequency tag change events occurring, disk speed, CPU availability, etc. For example, if it takes 5s to gather up and publish that payload, the actual message publish frequency will be it will be 5s + the flush period

Anchor
HistoryAdvanced HistoryAdvanced

History - Advanced

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