This property is used to control the generation of OnTagRead events, which occur in the I/O Driver that contains this I/O Block. If this property of an I/O Tag is set to True, the OnTagRead event generation is then enabled for that I/O Block. Otherwise, it does not occur. I/O Tags, I/O Blocks, and I/O Block Elements can generate this event. The event occurs in the I/O Driver, not in the I/O Block.