Re: X10 TM751 and "runaway" dims???

[nobody@xxxxxxxxxxxx (Dave Houston)]

nobody@xxxxxxxxxxxx (Dave Houston) wrote:

>No. The RF code includes address and function in one code. For example...
>
>A1 ON 01100000 00000000
>
>The RF encoding is described (partially) in the CM17A documentation. The
>payload bytes are the same as the 3rd & 4th bytes sent to the CM17A with the
>RF protocol being identical to the NEC IR protocol. The old rectangular
>keychain remote used a µPD6121 NEC chip to generate the codes.
>
>     www.cpcares.com/pdf/UPD6121G-001.PDF
>
>Each of the two payload bytes are followed by their bitwise complements (B1
>'B1 B2 'B2) and the bits are sent in reverse order. See p5 of the PDF.

Here's an example. I used "B2 ON" because A is 0110 which is symmetrical and
doesn't make the bit order clear. In the bitstreams below spaces are
meaningless in the transmission scheme - they are just there to delineate
sections of the codes. The ------ represents 6 idle PLC half-cycles.

B2 On (RF) -> B2, B On (PLC)

RF: Lead-In 01110000 10001111 00010000 11101111 (40ms silence)

PLC: 1110 10101001 1010100101 1110 10101001 1010100101 ------ 1110 10101001
0101100110 1110 10101001 0101100110

RF codes are usually repeated 5 times. PLC is always sent twice.