Node Discover response has additional data

[Alistair Adams]

I'm on is day 2 playing around with the Python library and my Raspberry Pi. Progress was great until I stalled when trying to send a Node discover Command in API mode. _parse_ND_at_response() was complaining because there were too many bytes in the parameter data. Tracking this down a bit further and it turns out that I'm getting the Device Type Identifier at the end of the parameter data (an extra 4 bytes) and this is not expected. Not only is it not expected by the Python library its not in the documentation either. 

I'm looking at Digi latest documentation (http://ftp1.digi.com/support/documentation/90000976_W.pdf) dated 2015 and the response is documented on p176 but doesn't mention the Device Type Identifier.

My firmware versions are 23A7 in my Router and 21A7 in my Coordinator.

I'm not dead in the water and can modify the library to get around this but that doesn't seem right.

Thoughts from anyone?

-Alistair