I'm not sure if the summit24's have that capability, I just compared my summit24 to my BlackDiamond. The BD has the enable web cmd, where as the summit24 doesn't. I know in order to receive the port utilization and errors from a switch into the the RT stats of EPI center you need to enable RMON, if RMON is disabled you can still pole it into inventory as long as your SMNP config is correct.
Radar telnet into your switch and type 'enable rmon' without quotes, hit enter, then check your RTstats in EPI Center. Otherwise do as Comstocb said and call the 1-888-257-3000,