The best replacement for bacnet is modbus.

The best alternatives to bacnet are rated as following:
★★★★★  modbus
★★★★  lonworks
★★★★  lon
★★★  lontalk
★★★  knx
★★  opc
★  n2
★  scada
★  lonmark
  obix
  lonwork
  native bacnet

Your alternative for bacnet is not listed? Suggest!
Speaking about bacnet, one probably shouldn't forget about plc.

Other search terms related to bacnet and their ratings are:
★★★★★ plc
You have in mind a companion for bacnet and it is not yet here? Propose!



Google Trends

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bacnet
modbus
lonworks