[mh] Insteon PLM May Perform Better When Isolated from the Powerline

[Kevin R. K. <ke...@kr...>]

This is a note about my experience that may help others.

My PLM has been exhibiting a binary state for some time:
1. The majority of the time,  the PLM is able to communicate with all
of my devices with almost no error. (I would estimate less than .1% of
messages need to be repeated)

2. Intermittently, the PLM would have a hard time communicating with
nearly all of my devices. (error rates would increase to about 3%)
Some devices seemed to be more affected by the problem than others.

I tested the normal things, replacing devices, filtering other items
in my house, testing with everything in the house turned on and off,
unplugging my PLM and plugging it back in again.  Nothing really
provided a lasting result, solutions that worked one day, would fail
the next.

I found an old post in the homeseerer forum, five or more years old,
suggesting that a user plug the PLM into the FILTERED side of a
filterlinc.  This essentially would disable the PLM's ability to
communicate using the powerline and would force it to use the rf
signal only.

After a few days of testing, I can say that this solution is working
spectacularly for me.

In looking at the insteon spec I can only surmise the reasons why this
works.  According to the spec, powerline signals are actually
transmitted before sending the rf signal for each hop.  A standard
insteon message takes about 50 milliseconds to transmit. Devices send
the powerline messages in the first 40 milliseconds.  The next 10
milliseconds are reserved for sending the same message via rf.

My theory is that because the powerline signals arrive first, the PLM
defaults to relying on these, even when the signal is weak or the
message is incomplete.  My other theory is that the static in my line
was soo bad, that it was causing interference throughout the PLM (I
really don't think this is the case).

Either way, it works well for me.  It also appears that smarthome is
going down the same path.  They no longer sell their Homelinc system
with a powerline PLM, it only comes with the USB dongle rf only PLM.