TimeDomain – OPC Unified Architecture – Part 11: Historical Access

3.1.10 TimeDomain

interval of time covered by a particular request, or response

Note 1

Note 1 to entry: In general, if the start time is earlier than or the same as the end time, the time domain is considered to begin at the start time and end just before the end time; if the end time is earlier than the start time, the time domain still begins at the start time and ends just before the end time, with time "running backward" for the particular request and response. In both cases, any value which falls exactly at the end time of the TimeDomain is not included in the TimeDomain. See the examples in 4.6. BoundingValues effect the time domain as described in 4.6.

All timestamps which can legally be represented in a UtcTime DataType are valid timestamps, and the Server may not return an invalid argument result code due to the timestamp being outside of the range for which the Server has data. See OPC 10000-3 for a description of the range and granularity of this DataType. Servers are expected to handle out-of-bounds timestamps gracefully, and return the proper StatusCodes to the Client.