isvalid

Determine whether instrument objects are valid

Syntax

out = isvalid(obj)

Arguments

`obj`	An instrument object or array of instrument objects.
`out`	A logical array.

Description

out = isvalid(obj) returns the logical array out, which contains a 0 where the elements of obj are invalid instrument objects and a 1 where the elements of obj are valid instrument objects.

Examples

Suppose you create the following two GPIB objects:

g1 = gpib('ni',0,1);
g2 = gpib('ni',0,2);

g2 becomes invalid after it is deleted.

delete(g2)

isvalid verifies that g1 is valid and g2 is invalid.

garray = [g1 g2];
isvalid(garray)
ans =
     1     0

Tips

obj becomes invalid after it is removed from memory with the delete function. Because you cannot connect an invalid object to the instrument, you should remove it from the workspace with the clear command.

Version History

Introduced before R2006a