Some of the units in the stack will contain a mechanism for drawing attention to that unit. This is useful for directing maintainance personnel. The method often employed is for a special LED, or by placing some other LED into a flashing state. This object gives access to the attention mechanism for a unit. Note that if a unit does not support this mechanism then reading the value of this object will return 'no-such-name' error. The possible values for an instance of this object which does exist is 'noAttention' or 'attention'.