I have ran into this issue quite a few times in the last weeks, Everything works well in general but for an unknown reason the EZIO8SA stops responding and then I can hear the relays click about every second.
If I unplug the 8SA from the PLC (hard reset!) and then replug it, it goes back to working well for a while (between 1 hour and a couple of days)
Dan, if you are hearing the relays click once per second, it would seem that the unit somehow is being put in diagnostics mode. This would be command 0x4F/0x0E. To take it out of this mode, it would have to get command 0x4F/0x0F