Description: When the NIU is initialising, this identifies which s/w image should be used.

boot - identifies that this s/w should be used at initialisation. There must be one s/w version with this action and there must be only one. backup - is used to identify a s/w version to use in the event that the boot version fails. Multiple s/w versions may have this action. In this case they will be tried in slot order. none - is used to identify a s/w version that is not used at initialisation. emptySlot - identifies the slot as containing no s/w. If this is applied to a slot that currently contains a s/w image the image will be erased and not identified in the slot.