Connecting to the VTN

The VTN (Virtual Top Node) is a separate backend Django appliance running from a different codebase. It is the ‘command and control’ server for the demand side reponse system, implementing a VTN (virtual top node) as described by the OpenADR protocol. It sends information about demand response events to the HEMS. A HEMS is assigned both a Site ID and a Customer ID in the VTN.

Data on these events is made available to the PowerShaper Flex application by an API. An API key is needed and is saved as an environment variable (VTN_API_KEY). Users can use the PowerShaper Flex interface to opt out of (and back into) events - this is also communicated to the VTN using an API call.

The base URL for the API for the VTN corresponding to this environment (development, staging or production) is stored in the environment variable VTN_API_URL. The URL for the admin interface is stored in VTN_GUI_URL.