DataHub Scripting : Version 6.4
	Time Conversion Functions from Time.g

`PointMetadata`

PointMetadata — queries a point for its metadata structure.

Syntax

PointMetadata (point)

Arguments

point: The fully-qualified symbolic point name of a DataHub point.

Returns

Either a DH_Item structure, or nil.

Description

This function queries a point for its metadata structure, which is a DH_Item containing the following fields:

item.canonical_type

A number representing the canonical type of the point. See the possible values of VARTYPE in Windows:

`VT_EMPTY`	`= 0`
`VT_I2`	`= 2`
`VT_I4`	`= 3`
`VT_R4`	`= 4`
`VT_R8`	`= 5`
`VT_CY`	`= 6`
`VT_DATE`	`= 7`
`VT_BSTR`	`= 8`
`VT_BOOL`	`= 11`
`VT_I1`	`= 16`
`VT_UI1`	`= 17`
`VT_UI2`	`= 18`
`VT_UI4`	`= 19`
`VT_I8`	`= 20`
`VT_UI8`	`= 21`
`VT_INT`	`= 22`
`VT_UINT`	`= 23`

item.conf

A number from 0 to 100 indicating a confidence factor.

item.flags

Any bitwise combination of the following numeric set of flags:

`DH_ITEM_READABLE`	`0x0001`
`DH_ITEM_WRITABLE`	`0x0002`
`DH_ITEM_LOCKED`	`0x0004`
`DH_ITEM_PROPERTY`	`0x0008`
`DH_ITEM_SUBASSEMBLY`	`0x0010`
`DH_ITEM_ASSEMBLY`	`0x0020`
`DH_ITEM_ATTRIBUTE`	`0x0040`
`DH_ITEM_TYPE`	`0x0080`
`DH_ITEM_ACTIVE`	`0x0100`
`DH_ITEM_PRIVATE_ATTRIBUTE`	`0x0200`
`DH_ITEM_PROCESSED`	`0x0400`
`DH_ITEM_HIDDEN`	`0x0800`
`DH_ITEM_AUTO_ID`	`0x1000`

item.opcaccessrights

Any bitwise combination of 1 for READABLE and 2 for WRITABLE. The same as the first two bits of item.flags.

item.quality

The OPC quality value. You can get the name associated with the value by using the GetQualityName function in the Quality.g file. Put the statement:

require ("Quality");

at the beginning of your script to gain access to this function.

item.scan_max

Maximum scan rate on this point. Not in use.

item.security

The security level on this point.

item.timeoffset

Offset in seconds from local clock time for the originator of this point value. Not in use.

item.timestamp

The Windows time stamp of this point.

The point metadata is likely to change in the future, though the actual fields available will remain the same. It would be good practice to wrap access to the metadata within wrapper functions.


PointGetWindowsTime		UnixLocalToUTC