I'm running an ISY994i to control my vacation rental.  Back in October my PLM stopped working.  I did not find this out until I made a site visit in mid-November.  Is there anyway I can poll the PLM periodically and send a message if the ISY doesn't get a proper response?  Are there any ISY system status/state variables I can write logic around for this purpose?  Can I use any of the device variables and properties listed on the Wiki ISY-994i_Series:EMail_and_Networking_Substitution_Variables page for this purpose? 
  
  
Thanks,