Patton 4114 Line Detection

[3cx-user]

So I am currently testing our PSTN lines after only testing with a VOIP setup and am testing with the Patton 4114. My question is does this actually do any verification that the line is good or even plugged up? I was hoping that the system would detect a dead line and not use it so for example if one of the lines went dead or all of the PSTN lines failed for some reason that it would route to the VOIP.