About a few months ago, I upgraded my Boy 15S with a PLC. The PLC I am using is overkill but it gives me numerous options. I gave up on my german diagram as it was easier to completely gut the cabinet including the analog temperature controllers. I listened for clicks for the solenoids and I then connected all of the switches to the PLC. I closed a limit switch and recorded the position on the PLC. After renaming the switches and solenoids to my preference and some simple coding, I am running.