BACnet - A Data Communication Protocol for Building Automation and Control Networks

Here is a summary of the various BACnet Standards

Standard	Protocol Revision	Services	Objects	Addendum	Changes
	0	35	18	g
	1	37	21	g
	2	40	23	g
	3	40	23	g
	4	40	25	g
	5	40	30	g
135-2004	?	?	?	g	Network Security Object
135-2008	?	?	?	g	Network Security Object
	?	?	?	j	Access Credential Object
	?	?	?	w	Bitstring Value Object Characterstring Value Object Date Pattern Value Date Value Datetime Pattern Value Integer Value Large Analog Value Octetstring Value Positive Integer Value Time Pattern Value[Time Value]]
135-2010	12	40	51	i	Lighting Output Object
	?	?	?	i	Lighting Output Object
	?	?	?	aa	Notification Forwarder Object Alert Enrollment Object Channel Object
	?	?	?	af	Channel Object
	17	41	57	ai
	?	?	57	az	Binary Lighting Output Object Network Port Object
135-2012	41	55

BACnet Standard