Ignition Tag History Synchronization

[Max555]

I have a question about the eWON connector module for Ignition.

If you are using the default DataMailbox connection, how does historical data synchronize with the Ignition tag history? I read that the eWON and DataMailbox can store and forward data. Do you enable history on your tags in Ignition? How does that work if you have historical data in DataMailbox that conflicts with historical data already in Ignition?

To be specific, let’s say you have a communication interruption. The tag value in Ignition will freeze. This frozen value will be recorded in the Ignition tag history. Later you reconnect and DataMailbox gets the historical values for the time in question. How do those values get integrated into the Ignition history?

Thanks,
Max

[deryck_hms]

Hi @Max555,

The timestamp used in the ignition database is set using log data stored in the data mailbox. intermittent connection issues generally should not be any issue.

You might want to keep in mind that data is pooled in two places, on the ewon itself in the historic logging file and then in the datamailbox. If the ewon looses its connection to the internet or for another reason is not able to push data to the data mailbox data will continue to be stored in the ewon. On an Ewon Flexy, you can store up to 1.000.000 points. This depends on its memory configuration, the default config allows 250.000 points. The data on the flexy is stored with FIFO so if the ewon is unable to push to the datamailbox the oldest data might get over written.

Discussing the time stamp with one of the developers involved in the connector they said the following.

For proper historical data storage on the Ignition system, a new historical tag provider should be added. Once a historical tag provider is added, on the connector configuration page, select “History Enabled” and then choose the created historical tag provider.

With a historical tag provider enabled, data is tracked from DataMailbox and data/timestamps are stored in the historical tag provider as they came from DataMailbox. In the event of a disconnect from the network, or other gap in functioning, the connector stores a transaction ID to ensure that it continues receiving the correct data from DataMailbox.