Open systems in building management systems

A communication protocol is a set of rules used to share data. An open protocol means the communication rules are publicly available. Using an open protocol is a good first step but can become complicated if a single vendor owns the protocol. That vendor could keep some of the features for only their products, making it less open than would first appear. Or worse, the vendor may change the protocol leaving existing systems in a state where an upgrade may break existing interoperability.