#BACnet Reference Stack for BeagleBone Black and EasyPHY Communications Modules
EasyPHY(TM) Modules allow manufacuturers (OEMs) of BACnet Native controllers to decouple their designs from the actual physical network requirements.
The manufacturer implements a single BACnet protocol layer (BACnet MSTP) on their controller and this is used to communicate, via a socket or wires, to an EasyPHY module.
Then, depending which EasyPHY module is installed, it simpley converts those BACnet MSTP messages to BACnet/IP, BACnet/IPv6, BACnet Ethernet, BACnet over WiFi, BACnet over Echelon's LIFT, messages.
The simplest EasyPHY module contains just an EIA-485 chip - and this enables a very cost-effective default of BACnet MSTP, yet allowing the more expensive other options to be substitued at any time - on the production line or in the field!
EasyPHY solutions come as plug-in daughterboards, or wire in (EIA-485 or logic-level) modules, or as preprogrammed chipsets for on-the-board assembly, with unique serial numbers, OUIs etc. They can be mounted on the controller motherboard via sockets, or via soldered in or screw terminal wiring harness to a board inside or outside the controller's enclosure.
ConnectEx, Inc. supplies the modules, and to enhance adoption, free hardware reference designs and free reference BACnet software, based on the very well established and popular open source stack by Steve Karg.
Reference source code for using EasyPHY interfaces on the BeagleBone Black platform based on the very popular open-source stack by Steve Karg at https://sourceforge.net/projects/bacnet/?source=directory
BACnet open source protocol stack for embedded systems, Linux, and Windows http://bacnet.sourceforge.net/
Welcome to the wonderful world of BACnet and true device interoperability!
This BACnet library provides a BACnet application layer, network layer and media access (MAC) layer communications services for an embedded system.
BACnet - A Data Communication Protocol for Building Automation and Control Networks - see bacnet.org. BACnet is a standard data communication protocol for Building Automation and Control Networks. BACnet is an open protocol, which means anyone can contribute to the standard, and anyone may use it. The only caveat is that the BACnet standard document itself is copyrighted by ASHRAE, and they sell the document to help defray costs of developing and maintaining the standard (just like IEEE or ANSI or ISO).
For software developers, the BACnet protocol is a standard way to send and receive messages on the wire containing data that is understood by other BACnet compliant devices. The BACnet standard defines a standard way to communicate over various wires, known as Data Link/Physical Layers: Ethernet, EIA-485, EIA-232, ARCNET, and LonTalk. The BACnet standard also defines a standard way to communicate using UDP, IP and HTTP (Web Services).
This BACnet protocol stack implementation is specifically designed for the embedded BACnet appliance, using a GPL with exception license (like eCos), which means that any changes to the core code that are distributed get to come back into the core code, but the BACnet library can be linked to proprietary code without the proprietary code becoming GPL. Note that some of the source files are designed as skeleton or example files, and are not copyrighted.
The text of the GPL exception included in each source file is as follows:
"As a special exception, if other files instantiate templates or use macros or inline functions from this file, or you compile this file and link it with other works to produce a work based on this file, this file does not by itself cause the resulting work to be covered by the GNU General Public License. However the source code for this file must still be made available in accordance with section (3) of the GNU General Public License."
The BACnet protocol is an ASHRAE/ANSI/ISO standard, so this library adheres to that standard. BACnet has no royalties or licensing restrictions, and registration for a BACnet vendor ID is free.
The BACnet stack was functionally tested using VTS (Visual Test Shell), another project hosted on SourceForge, as well as various controllers and workstations.
$ make clean all
$ demo/sever/bacsrv