In modern buildings, communication pathways and utility spaces are routinely provided. Historic structures, on the other hand, were not designed for routing cables or many other utilities (such as plumbing) that are standard today. We appreciate the craftsmanship and solid construction of these buildings and there is a desire to retain these architectural details and finishes while installing or modernizing a Building Management System (BMS) to comply with today's comfort, energy, and performance needs.
The challenge is how to install a modern BMS, such as BACnet, in an older structure with minimal impact. Fortunately, many older buildings have antiquated BMS systems in-place, using twisted-pair wiring. These wires are still serviceable.
It is possible to upgrade these buildings to a modern BACnet BMS using BACnet I/O modules and a Contemporary Controls BTL Listed BASrouter. This BACnet multi-network router provides versatile stand-alone routing between BACnet/IP, BACnet Ethernet, and BACnet MS/TP networks. The existing twisted-pair wires become a BACnet MS/TP network, with all the commissioning and troubleshooting features of BACnet. Multiple BASrouters allow you to consolidate discrete regions (such as floors or utility spaces) into a structure-wide system by installing a single CAT5 cable that links these areas together as a 10/100 Mbps Ethernet network. A wireless network solution is available as well, and we will discuss this in a future newsletter article.
The BASrouter provides troubleshooting and diagnostic capabilities. The BACnet MS/TP "Status" webpage contains a graphical table of all the MS/TP devices on the network and their status. Also provided are network statistics. In addition, a BACnet/IP "Routing" webpage with a discoverable routing table is useful when setting up or troubleshooting the BACnet network.
Another alternative, if Modbus I/O devices were used, is to utilize the Contemporary Controls BASgatewayLX to retain and allow these EIA-485 Modbus serial (RTU or ASCII) devices to appear as individual BACnet compliant devices that can be accessed and integrated into a modern BACnet Ethernet network. Contemporary Controls maintains a free library of pre-built Modbus profiles and will create new device profiles free-of-charge to make it very easy to integrate any Modbus device to BACnet. Multiple BASgatewayLX modules communicating over a single CAT5 cable (or wirelessly) can create a structure-wide high-speed BACnet Ethernet system from what was once a collection of discrete regions.