The answers regarding modbus will depend if one is using an actual X2 or the Xbee Gateway.
Assuming it's the X2, then Here's the Modbus Python Resource Page:
There is a lots of information there. The most relevant would be here (modbus Bridge on CPX4/2):
and to a lesser degree:
Assuming one is using the Xbee Gateway, then they would need to build all the modbus functionality they want using python. Unfortunately, the Xbee firmware doesn't support it by itself and Python would need to 'fill the gap'. In other words, all the features listed above they would have to write themselves.
Last updated: Aug 23, 2017