The Southern Illinois University system’s overseers say an interim chancellor should be on board on the Carbondale campus within weeks. WSIU radio reports that SIU President Randy Dunn says the temporary replacement to Arizona-bound Rita Cheng likely will be named in time for the university board’s next scheduled meeting July 24th in Springfield. Dunn and the system’s trustees discussed the matter during a special meeting Tuesday in Edwardsville. Cheng has been the Carbondale school’s chancellor since 2010. But she’s been hired as the new president at Northern Arizona University. SIU President Randy Dunn has said Cheng is to start her new job in Flagstaff in mid-August and, at least for now, scheduled to remain with SIU into next month.