Looks like the relay unit sets the brown wire (#2) to high for ~20ms then send a reset sequence and the height value in inches

0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 1 0 1 0 0 [BITS FOR HEIGHT]

Each bit is ~100us long (9,600 bps? My "logic analyzer" is a nice debug toy but can't get accurate readings out of it)

EDIT : ** Just confirmed that the relay unit is sending 16bit integers over 9600bps.

the format is [257][HEIGHT][257][HEIGHT]....

here are some samples -

32.9 = 1 0 1 0 0 1 0 0 1 0 (329 = 01 0100 1001)

32.8 = 1 0 0 0 0 1 0 0 1 0 (328 = 01 0100 1000)

32.5 = 1 0 0 1 1 0 0 0 1 0 (326 = 01 0100 0110)

32.4 = 1 0 0 0 1 0 0 0 1 0 (324 = 01 0100 0100)

32.1 = 1 0 1 0 0 0 0 0 1 0 (321 = 01 0100 0001)

31.8 = 1 0 0 1 1 1 1 1 0 0 (318 = 01 0011 1110)

29.8 = 1 0 0 1 0 1 0 1 0 0 (298 = 01 0010 1010)