Re: Insteon - watch out for RF interference

[nobody@xxxxxxxxxxxx (Dave Houston)]

"Mark Thomas" <mrt@xxxxxxxxxxxxxx> wrote:

>What's the difference between "Insteon PLC signals" and X10 signals?

They have updated their online specs. They still give few details but
there's enough to get the gist of what they are doing. Go to
http://www.insteon.net and click on "specifications".

The bit rate is high but they send lots of bits per command (192). Using
their sustained rate figure, they can send one command per half-cycle of the
powerline using BPSK modulation (which will make it tough for DIY hardware
design). Each command appears to end in an 8-bit checksum and all commands
are acknowledged. I suspect they will have X-10 like problems with
continuous noise and signal suckers (They have phase couplers and filters.)
but the high bit rate, checksums, acknowledgements and repeats should
provide decent reliability in the face of sporadic noise.

Their RF 'network' has no routing tables so its repeaters just fill the
vicinity with the signal. The number of repeaters will need to grow
geometrically with the size of the area to be covered.

They use a low PLC signal level but each Insteon device repeats the signal
so they probably get adequate coverage.

They give no details for the RF other than carrier frequency and modulation
(904MHz FSK).

By "X-10 compatible" they appear to mean it can coexist with X-10 although
their desktop controller can send Insteon or X-10 PLC. The Insteon modules
do not repeat X-10 PLC signals. There's no compatibility of the RF
frequency/protocol.