Edge Computing with BACnet devices
October 24, 2017
Our client, building automation system integrators in Canada approached us for an IoT Gateway solution that can implement Edge Computing with multiple BACnet devices under it. Even though there is a direct authenticated communication channel between web based Building Automation System (BAS) and a BACnet device, certain data processing need to be performed at the building level; without dependency on internet.
A NodeRED based IoT Gateway is proposed, planning to leverage the BACnet nodes and perform edge computing. However the set nodes had many issues and finally we had to develop custom nodes in Node-RED that can communicate with BACnet devices. The BACnet protocol and the semantics of standard objects and properties are learned.
Two sets of custom nodes were developed for edge computing: one pair of nodes to perform read/write functions on a BACnet device, and the other pair of nodes performs the read/write functions and is seamlessly integrated with BAS over HTTP. The node specifically fetches the “present_value” property of the BACnet device. The read values will be then pushed to the BAS application hosted in the cloud; authenticating using username and password. Write commands from BAS are received at the Gateway and is issued as BACnet write message to the configured BACnet device.
Main Hardware Used:
Client: System Integrator and Edge Computing