set_canonical
set_canonical — sets the
type of a point.
Syntax
(set_canonical pointname canonical_type [force])
Arguments
- pointname
- The full name of the point, with
domain.
- canonical_type
- Either a number with a legal numeric
VT_TYPE value, or one of:
I1, I2,
I4, UI1,
UI2, UI4,
CY, DATE,
BOOL, BSTR,
R4, R8,
EMPTY, I1 ARRAY,
I2 ARRAY, I4 ARRAY,
UI1 ARRAY, UI2 ARRAY,
UI4 ARRAY, CY ARRAY,
DATE ARRAY, BOOL ARRAY,
BSTR ARRAY, R4 ARRAY,
R8 ARRAY.
- force
- A
value of 1 forces a change in canonical
type. A value of 0, or the omission of
this optional parameter, will allow the canonical type to
change only if it is currently
EMPTY.
Returns
A message indicating success or
error. Please refer to Return
Syntax for details.
Description
This command sets the canonical
type of a point. Normally a point's canonical type is
EMPTY, meaning that it will maintain the data
type of whatever data is written to it. If the canonical type is
other than EMPTY, then any data written to the
point will be converted to that type before it is stored.
![[Note]](images/note.gif) | When a point has a non-empty canonical type it is possible
that the conversion could fail, in which case the point value is
not changed. |
