8.57 AccessLevelType
This is a subtype of the Byte DataType with the OptionSetValues Property defined. It is used to indicate how the Value of a Variable can be accessed (read/write) and if it contains current and/or historic data. The AccessLevelType is formally defined in Table 40.
| Name | Bit | Description |
|---|---|---|
| CurrentRead | 0 | Indicates if the current value is readable. It also indicates if the current value of the Variable is available. (0 means not readable, 1 means readable). |
| CurrentWrite | 1 | Indicates if the current value is writeable. It also indicates if the current value of the Variable is available. (0 means not writeable, 1 means writeable). |
| HistoryRead | 2 | Indicates if the history of the value is readable. It also indicates if the history of the Variable is available via the OPC UA Server. (0 means not readable, 1 means readable). |
| HistoryWrite | 3 | Indicates if the history of the value is writeable. It also indicates if the history of the Variable is available via the OPC UA Server. (0 means not writeable, 1 means writeable). |
| SemanticChange | 4 | This flag is set for Properties that define semantic aspects of the parent Node of the Property and where the Property Value, and thus the semantic, may change during operation. (0 means is not a semantic, 1 means is a semantic). |
| StatusWrite | 5 | Indicates if the current StatusCode of the value is writeable (0 means only StatusCode Good is writeable, 1 means any StatusCode is writeable). |
| TimestampWrite | 6 | Indicates if the current SourceTimestamp is writeable (0 means only null timestamps are writeable, 1 means any timestamp value is writeable). |
| Reserved | 7 | Reserved for future use. Shall always be zero. |