• Add Push Buttons or Toggle switches to a Switch8 Mk2
• Make Local Control Panels with NO programming.
The length of the wiring in and out of the button board will depend on the type of wire used. The more twists per foot, the longer the wire can be before noise introduced. Flat untwisted would be where the two feet rule comes in. On the other end of the spectrum you have pre twisted hookup wire that should be able to go 30 feet before causing issues.
I have attached a picture of the twisted pair cable we use for this situation.
The button board sends two bytes of data (9600,N,8,1) for each button 'event'
The first byte is the actual button data and the second byte is a complement of the
first. The second byte when XORed with the first should yield 0xff allowing a
modicum of error checking.
The button data is as follows (in binary):
1000 nnnn = button pressed, nnnn is the button number (0-F)
0100 nnnn = button released, nnnn is the button number (0-F)
Bits 4 and 5 are reserved and may represent additional button numbers in the
future so clear both bits when talking to a device that only expects up to 16 buttons.
Some devices may choose to ignore button released events.