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The function goal_opcUaEventTrigger is used to trigger the event that is specified by its node ID.

Date Time base

This part only describes the GOAL OPC UA server stack. The open62541 stack uses the Linux time stamps to create current date time values. All API, which is presented here, will return a “Not Supported“ GOAL error code.

OPC UA messages contain a current data time value. Because not all platforms support a Real Time Clock (RTC), the data time must be emulated. Therefore, a data time value is stored at a specific time, and the tuple (date time, timestamp) is used as base to create date time values on given timestamps. Before a valid date time is extracted, the stack uses 0 values for date times, which are interpreted as “unset“ or “unused“. The tuple (date time, timestamp) can be created in two different ways.

  • Automatically: In this case, the stack tries to extract current date times from client messages. After the first successful extraction, the tuple (date time, timestamp) is used for all further calculations.

  • Manually: If an external time source is used (e.g. linux, a RTC or any other protocol), the stack can be informed directly using the function goal_opcUaDateTimeSet. Therefore, the current date time must be calculated, which is defined as the number of 100ns steps from 1601-01-01T00:00:00.000 (UTC) encoded as 64-bit integer. E.g. 1970-01-01T00:00:00.000Z corresponds to the date time value 0x019db1ded53e8000. This function could be called multiple times, overwriting the last tuple (date time, timestamp).