Parts that can be placed differ depending on
the instruction.
30.13.1.5 Instructions that
use Drag and Drop
When more than one part can be placed, the
possible parts will be displayed.
If you drag an instruction that cannot be
placed, the action will be canceled.
Click [Cancel] to cancel the part
placement.
Where the pointer is displayed with 
, you cannot place
parts.
When structure variables are allocated to
ladder instructions, all integer variables and bit variables are
displayed.
, release the left
mouse button.
