I am on a current modern PLM on my esiy.

I recently got a lot of older parts from ebay which included many USB and Seriel PMLs, some are quite old, all 2413U and 2414U

Knowing the future is Insteon is uncerten ( hope not, but not sure they are that popular anymore and their devices cost much more) I'll keep a few of these as spares, but a few questions.

1. Can IOX restore from a newer to an older PML?

2. Is it no issue to go between serial and USB PLMs? (I have never used USB)

3. Is there an easy way to test these PMLs to see if they are good or if some need re-capping or or just dead? Or is it really just wait until it's needed and if it works it works?

2414U is not a PLM. It is PLC Power Line Controller. Could have programs downloaded in to it and run on its own. You had to create a program. Then use their compiler to compile it and down load it to the 2414U OR 2414s. With the SDM Smarthome Display Manager running the program. I believe it was Windows only.

2413S and 2413U are the same except the interface daughter board to the outside world. If sent the PLM ID command. It will have a different Subcategory. Most programs I know of did not check it and still worked fine. Subject to the known capacitor issues we have seen in the older revisions.

Thanks! That is super useful I didn't know about the PLC, these did all come with Indigo stickers on the boxes so I'm guessing that system used it. This likely means they are not useful for me. I can post them it's not clear to me there is a market for them anymore.

For the PLMs though I am interested in, still curious if there is an easy way to test short of unplugging my current one, doing a restore see if things fail etc.

BusyRat gave us PLM test program but you had to know the low level commands and saw how it responded. I believe it was serial port only and in Windows. Developers also got some test programs through DockLight. Using the free downloadable evaluation version. I rewrote a few of the test programs to do what I wanted. Secret was their ptp programs could be rewritten with a plain text editor. If you knew what lines to change. As one of the limits of the free version was you could not save the changes. I did use it modified to do USB PLM units.

So technically yes you could test them but it was not easily done by most. I would think the PLC modules are best in the electronic recycle bin.

@brockp , it appears that Houselinc is still available here: https://support.insteon.com/support-knowledgebase/2016/6/1/houselinc-windows

HouseLinc is a PC based interface for Insteon control. It was the forerunner of Smartlabs Hub based system.

I still use Houselinc for it's diagnostic/signaling capabilities. I have it setup on a Windows 11 mini PC with a USB to serial adapter to the PLM.

The following was a test that I ran after having issues to a new refrigerator install. Houselinc ran 1000 tests on 17 different devices and rolled up the success %. I had "Disable PLM Retry" selected and "Hops" set to 2, so this was similar to a standard ISY scene (no retries, HOPS=3).

You could certainly use this to give your questionable PLM's a workout. 1 word of caution - using Houselinc to link to existing devices will alter their link tables (without the ISY's knowledge). Make sure to use the ISY to restore the Link tables after testing.