[BScout]

You need Sync HD or Sync X (Sync IO will not work)

Feed the word clock out from the MTRX to the Sync. Don't use loop sync. Don't feed the Sync word clock to the MTRX. In DADman, set the MTRX to reference clock from the digilink. In Pro Tools Session Setup, tell the clock reference to be the Sync HD word clock in.

That's it (other than the serial cable to the HDX card from the Sync and the setup in Peripherals)