I implemented DCC by writing code to place 0s and 1s on the track. I can generate a single-byte DCC instruction, send it to the decoder, and get the engine to change speed, change direction, or stop. I can also implement a single-byte '100' function group one instruction to turn lights on and off. Using S-9.2.1 extended packet formats I had hoped to implement a two-byte control instruction, sending a speed byte followed by a second "100" headlight byte, and get them to operate at the same time. Unfortunately, I can still only control the motor and not the lights. The second byte is ignored. Any suggestions will be appreciated.
I had naively assumed that I could send a single-packet instruction to control the motor, then send another single-byte instruction to turn the lights on. Unfortunately, The second packet turning on the lights, cancels the first packet controlling the motor.
Thanks in advance