BACnet is the most popular open protocol found in building automation and energy management systems. The intent of this open standard is to allow building owners and systems integrators the opportunity to pick and choose BACnet-compliant equipment from various vendors.
BACnet client devices initiate commands while BACnet server devices respond to commands. BACnet devices communicate to one another over a network. The more popular networks include the Internet Protocol (BACnet/IP) and the Master-Slave Token-Passing network (BACnet MS/TP). Interconnecting BACnet networks requires BACnet routers while connecting non-compliant BACnet devices, such as Modbus, to a BACnet network requires a gateway.
The BASrouter is a BTL Listed compact BACnet multi-network router which provides versatile stand-alone routing between BACnet/IP, BACnet Ethernet (ISO 8802-3), and BACnet MS/TP networks. The BACnet router is web page configurable and it is powered by 24 VAC/VDC. The BASrouter has a number of troubleshooting/diagnostic capabilities. The BACnet MS/TP "Status" webpage contains a graphical table of all of the MS/TP devices on the network and their status. Also provided are network statistics, in addition to a BACnet/IP "Routing" webpage with a discoverable routing table which is useful when setting up or troubleshooting a BACnet network. Wide temperature operation makes it suitable for indoor or outdoor use.
The BASrouterLX is a high-performance BACnet router with diagnostic capabilities, providing stand-alone routing between BACnet networks such as BACnet/IP, BACnet Ethernet, and BACnet MS/TP. Besides its high- speed processor, it has advanced features such as MS/TP slave proxy support (allowing auto-discovery of MS/TP slaves) and MS/TP frame capture. As a BBMD, up to 50 BDT and 147 FDR entries are supported. The BASrouterLX has two physical communication ports — a 10/100 Mbps BACnet/IP Ethernet port and an optically-isolated EIA-485 port for MS/TP. Router configuration is accomplished via web pages.
The Portable BASrouter provides the same stand-alone routing and network diagnostics as the standard BASrouter in an even more compact case. Powered through a USB port, it could be connected to a laptop PC for fast and easy commissioning or quick network analytics. Configuration and commissioning accomplished via web page.
Modbus remains a popular network interface, and is commonly found on jobs such as boiler control, variable speed drives, and metering applications, but these devices lack BACnet compliance. To make Modbus devices appear as individual BACnet devices a BASgatewayLX is used. This device has one 10/100 Mbps Modbus TCP and BACnet/IP Ethernet port and an opto-isolated Modbus EIA-485 serial port for Modbus RTU or Modbus ASCII devices. Up to 100 Modbus serial devices represented by up to 1000 polled points can share the single Modbus EIA-485 port on the BASgatewayLX. BACnet COV notification is supported on 200 points (100 Analog and 100 Binary points). The virtual routing feature in the BASgatewayLX allows each connected Modbus device to appear as an individual BACnet compliant device. What is needed is a device profile for each Modbus type device.