OperationStates (GVL)

InOut:

Scope	Name	Type	Initial	Comment
Constant	PB_NOT_ENABLED	WORD	0	Operation not enabled
	PB_INVALID_PARAMETER	WORD	1	Invalid parameters
	PB_PENDING	WORD	2	Operation is still pending
	PB_DONE	WORD	3	Operation successfully ended
	PB_ERROR	WORD	4	Operation ended with error