We have reached the point where any new (or replacement) BAS is expected to support one or more open protocols. It also is an expectation that when we specify large pieces of equipment or even complete subsystems, that they will also be able to support open protocols. In theory for the designer, systems integration is readily accomplished, but in reality, there is still a fair amount of work needed to design and specify systems and equipment for ready integration. Here is what we look for in developing an integrated systems design.
Protocol Support. This may be somewhat obvious, but both the BAS and the system to be connected need to be able to support the same protocols. We generally start by checking with potential suppliers to see what options for connectivity they offer. Most of our designs are based around BACnet, but some equipment and systems may only have options for Modbus or other protocols. Once we settle on a systems integration protocol, the next step is to specify a physical link. This is generally an IP connection, if possible, but can also be a BACnet MSTP (RS-485) connection as well. If using MSTP, be sure to specify the communications rate, and ideally place each system to be integrated on a dedicated link to simplify testing and checkout.