bitmask¶

Canonical path: o6.bitmask

bitmask ¶

bitmask(
    value, *, name=None, description=None, displayName=None
)

Declare one bit of an OPC UA OptionSet.

Used as the assigned value of a member in an @o6.optionsettype class body. value is the member's mask, not its bit position — write it as 0x01 << n so the source shows the bit position and the value it produces at once.

@o6.optionsettype(ns="plant", base=o6.Byte)
class AccessLevelType:
    CURRENT_READ = o6.bitmask(0x01 << 0, name="CurrentRead")
    HISTORY_WRITE = o6.bitmask(0x01 << 3, name="HistoryWrite")

This is not an alias of o6.enumfield: an enumeration member and an OptionSet bit are different things, so each decorator accepts only its own helper.

Parameters:

Name	Type	Description	Default
`value`	`int`	The member's bit mask. Exactly one bit must be set, and it must lie inside the width of the OptionSet's declared `base`.	required
`name`	`Optional[str]`	OPC UA member name, for a UA name that is not a valid Python identifier.	`None`
`description`	`Optional[str]`	Description of the member in the `EnumDefinition`.	`None`
`displayName`	`Optional[str]`	DisplayName of the member in the `EnumDefinition`.	`None`

Returns:

Type	Description
`int`	A value that behaves as the member's `int` and carries the metadata until
`int`	the decorator consumes it.