What could possibly be the effect of shorting together of the two grounds of an isolator chip? Can there be any advantage of such an arrangement over keeping both the sides completely isolated including the signal grounds? My application involves use of ADM3251E RS232 isolation device. Can such use help in bypassing the common mode voltage between the two sides in a better way? Can it be more effective in tackling the ESD that may appear on the RS232 interface signals? And lastly, will the benefit of using isolation chip will continue to accrue at least as far as the data signals isolation is concerned?