My EISY has lost contact with all of my Insteon Devices. I have been operating normally with eisy/insteon for a year or two, but now, the eisy cannot effectively communicate with any of my insteon devices. I am using a 2413S PLM (Address 2B.93.EB) The PLM is attached to the eisy via a Serial-USB cable. The PLM Info/Status comes back with , "3B.93.EB /Connected." When I do the PLM diagnostic for PLM, the system goes through and extensive set of pop-ups where it seems to be doing a "Restore Modem (PLM) procedure. After completing the pop-up sequence I can send commands from the Admin Console t turn things On and Off, but the device does not actually respond. Some devices show the device turning on and off (without actually responding). Other devices get a pop-up saying "Cannot Communicate with [deviuce name]. Please check connections." The device then gets a red exclamation point on the Admin Console Main list. I have another 2413S PLM (Address 3D.95.E3). What is the procedure for swapping it in while doing the least damage to may rather extensive system?