That's a tough one....
The PRDT line runs into the 6500/1 MC - seems to be used with a serial protocol. Unless anyone has access to developer infos it'd be a lot of work to find out how it's working. The SM doesn't detail anything around here. It's probably much easier to circumvent the 6500/1 and tap into the lines in known territories, as explained in the link Cignale came up with.
