Building Automation: BAS use of Ethernet/IP Infrastructure
All of the world’s communications systems appears to have converged on the use of the Internet Protocol (IP) with Ethernet connections being the preferred method for local connection.
BAS systems have standardized on this type of connection, and many owners are looking to a future where even the VAV box and light switch will be on the network. If so, then why has this issue become one of the most vexing BAS design challenges? Simply put, should a BAS use its own dedicated Ethernet/IP system, or should it use that which is provided for the building’s business-enterprise communications and managed by the IT department?
For us, there are many obvious reasons why the use of the enterprise network is the right solution.
- Dedicated BAS Ethernet/IP communications is a
duplication and an added construction cost.
often requires additional specification design by the BAS designer
(for the dedicated Ethernet/IP system) - another added
- Without careful coordination,
the BAS Ethernet/IP equipment may not meet the facilities’ IT
standards (even though it is a separate system, this still can be a
concern to IT folks).
networks are typically higher quality, offer higher reliability, and
are actively managed with staff ferreting out potential attacks and
- Determining how and where
the Ethernet/IP LAN connects to Internet (for remote communications)
can sometimes lead to confusion.
We are also not the ones that are justifiably concerned with the risks of connecting building systems to the enterprise network including potential traffic, threats, and other issues that could potentially wreak havoc with the IT infrastructure.
Unfortunately, as BAS designers, we are not always best equipped to argue these issues with IT experts, and frankly they are not always the most open and receptive folks to work with.
Clearly, the BAS designer is faced with the choice between fighting for what is believed to be the best engineering approach vs. taking the path of least resistance by avoiding the potential IT battle. You could say that this is an example of the consulting engineer’s dilemma when confronting many building design issues. Also, it is not to say that placing the BAS system on the enterprise network is not without its challenges, which range from other IT coordination issues to schedule impact to network security. We’ll cover that side of the issue in a future column. ES