Which /dev device is the sled serial port connected to?
I see ttyS0, ttyS1 and ttyS2 are present at boot. All attempts I have made to see the device I have connected have failed dismally. It does not need any DTR/RTS/CTS signals (The PC side of the cable has RTS/CTS/DTR tied to ground. The device is working fine on my laptop.

Also are the RX/TX pins of this port crossed over or not?

Is any special configuration needed to stop the player software trying to use the sled port for anything? I have hijack suppress_notify=1

Help appreciated.