June 2011 - Veris Industries, a leading supplier of power monitors, environmental sensors, and control peripherals for commercial HVAC and energy applications, has published an application note that explains how the BAS Remote can act as a Modbus-to-BACnet IP gateway for the Veris Enercept Energy Meters.
Veris Enercept Energy Meters are widely used for monitoring energy consumption, but their communication link uses Modbus protocol. Many building automation systems are now using BACnet, resulting in an abundance of Modbus Serial equipment, like the Enercept Meters, that need to attach to the building automation system.
As stated in the Veris application note, "The BAS Remote acts as a Modbus-to-BACnet IP gateway. Multiple Enercept meters can operate with a single BAS Remote, reducing commissioning costs for large projects."
There are two ways the BAS Remote can attach Modbus Seriel to a BACnet network. The first approach is to route Modbus Serial messages from the BAS Remote Master MB port to Modbus TCP clients residing on Ethernet. This is the simplest approach requiring minimal configuration. The BAS Remote Master would act as a proxy for a Modbus TCP client, initiating a command to a connected Modbus Serial slave. When the slave responds, the message is forwarded to the Modbus TCP client. The resident BAS Remote Master I/O can be queried in a similar fashion by simply assigning this I/O a non-conflicting Modbus address on the device's web page.
The second approach is to utilize the gateway capability within the BAS Remote Master. Using an off-line spreadsheet, Modbus registers and slave addresses are mapped alongside BACnet object instances. The spreadsheet creates a CSV file which is downloaded into the BAS Remote Master for periodic scanning. The result is that attached Modbus Serial devices can be viewed as BACnet objects.
"We're pleased that Veris recognizes the BAS Remote's Modbus mapping capability, which has improved the BAS Remote's ability to integrate different protocols on the same job," said Joe Stasiek, Sales Manager at Contemporary Controls. "In addition to the Modbus mapping, function block programming using Sedona Framework means even more open system protocols are supported by the BAS Remote."
The BAS Remote Master incorporates Sedona Virtual Machine (SVM) technology developed by Tridium and compatible with their Niagara Framework®. Using established Tridium tools such as Workbench, a system integrator can develop a control application using Workbench's powerful drag-and-drop visual programming methodology. Once developed, the program remains stored in the BAS Remote Master and executes by way of the SVM. The application can run standalone in the BAS Remote Master or interact with a program in a Tridium JACE supervisory controller over Ethernet. The number of potential applications is only limited by the imagination of the system integrator.
"The BAS Remote provides the versatility our customers demand," said George Thomas, president of Contemporary Controls. "The utility device provides additional input/output capability, routing and gateway functionality and now Modbus mapping and logic powered by Sedona Framework. It's a critical building multifunction tool."
Visit the BAS Remote product page for ordering information.