datavalue

OPC UA Timestamps: Source, Server, Gateway, and the One to Store

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A single time axis in milliseconds with four numbered points on it and four labelled boxes above: source at 0 milliseconds in the controller image, the OPC UA SourceTimestamp at 180 from a 250 millisecond poll, the gateway publish at 225, and the database arrival at 885 from a one second write batch, with a red double arrow spanning the whole 885 millisecond spread

Belt1_Current crossed 30 A at 11:42:13.412 UTC. The OPC UA server stamped that value 11:42:13.592, the gateway published it at 11:42:13.637, and the row reached the table at 11:42:14.297. One event, four times, 885 ms apart on a day when nothing at all was wrong. Store the second one. The OPC UA SourceTimestamp is the … Read more

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