So, I got a new dual band PLM and 4 dual band switches to strategically locate so that I can hopefully get my hop count down to 1.

 

I powered down the system and plugged in the new dual band plm and powered up the ISY, but I neglected to plug in the serial cable between the two until after all was powered up. I think this caused the problem.

 

I went ahead and did the restore PLM. It looked like it did the restore and then wrote new links to all the devices. Then I checked the PLM links table. . . . 0! The PLM wouldn't track any devices as expected. I tried repeating the restore it took about 2 seconds and wrote nothing.

 

Now, I had no backup. Stupid right? I had a 6 day old backup but I had changed a bunch of stuff. Almost entirely programs. I can't remember, but I might have added a device to a scene. I did not add any new devices. I saw no way out but to backup my programs and then resotre the ISY to 6 days ago putting the old plm back on. Then I started the restore process all over again and this time it worked as expected. I then deleted the programs and restored the backup programs so I got all that back.

 

Here is the question.

 

I had a plm link count of 273 on the old plm

I have a plm link count of 266 on the new one.

 

What gives? Do I need to worry about this? All seems to be working. Should I just assume there were some orphan links?

I was adding some modules to my setup. So that My Lighting would show the devices firmware revision. Then deleting the modules in My Lighting. The PLM count was higher than before. I believe the links marked as deleted where still counted. When I did a restore PLM the count went back to what I expected.

OK, I have removed some defective devices since installing that old PLM.