Three more Iowa National Guard units are being put on alert for possible duty in Operation Enduring Freedom. Guard spokesman Colonel Robert King says the 234th Signal Battalion, headquartered in Cedar Rapids, has alerted 480 soldiers from companies based in Cedar Rapids, Clinton and Marshalltown. King says the soldiers may -not- be heading out right away. But, Colonel King says in some cases, units are put on alert status and mobilized for duty very quickly.King says the battalion’s mission is to provide wide area telecommunications support.