Getting Started with OpenADR

May 20, 2021

For those just getting started with OpenADR,  a short review.

OpenADR has 2 main components:

1. VTN – Virtual Top Node which schedules the Events (Usually 1)

2. VEN – Virtual End Nodes when given the proper security credentials, poll the VTN periodically for Events.

VEN’s are configured to respond to all Events or can be limited to participate only in those Programs defined by the VTN called “Market Context“.

 Because the OpenADR poll from the VEN is outgoing to the VTN there are no firewall issues except for highly restrictive networks that can be augmented by IT without compromising Cyber Security.

A VEN can be the final control device and respond to the Event by energizing physical relays or as an OpenADR gateway that passes binary or analog values to other systems via Modbus, DNP3 or BACnet.

The numbers of VENs is only limited to the VTN’s capacity to handle the communications traffic

OpenADR Virtual Top Node - End Node

OpenADR 2.0a emanated from the original OpenADR 1.0 introduced in 2010 which offers control of loads at 2 levels Moderate & High with a Pending notification that can range from 10 minutes (Fast DR) or up to 24 hours prior to the Event. All 3 have dedicated relays to allow the users to integrate into their system.

Moderate & High relays maybe connected to different loads as their name implies to reach the load shed contracted with the Utility or Aggregator. The Pending relay may control a beacon to notify plant personnel or initiate a pre-cooling strategy in the HVAC system to lessen the Event impact.

A 2.0a signal from the VTN would have 6 main elements:

Start Time (UTC)

Duration (minutes)

Market Context ID

Signal Name: Simple

Signal Type: Level

Payload Value: 1=Moderate 2=High 3=Special*

This is commonly called a Simple-Level Signal or 2.0a Signal.

*Special payloads do not correspond to relays and would need to be defined. See Special Signals.

OpenADR 2.0b offers additional capabilities beyond the Simple-Level Signal where more Signal Categories, Names & Types are available to create Load Shed, Energy Consume and Store strategies based on a higher level of data. It also has the capability to provide meter telemetry with configurable interval data back to the VTN.

This is an over simplification of the additional capabilities of 2.0b but this is how Utilities are generally using it today. It must be noted that in the OpenADR Alliance Certification process the VEN does not have to employ all the aspects of 2.0b and can opt out and not comply to certain parts and still remain 2.0b Certified. A device’s Certification can be reviewed on the OpenADR Products website site.

Energy Interoperation (EI) 1.0

Fig. 2

The OASIS Energy Interoperation (EI) 1.0 standard describes the coordination of energy supplies,
transmission, distribution, and usage. However, as shown in Figure 2, the features required
within the OpenADR 2.0 Profile Specifications are a subset of this Energy Interoperation

Signal Name











Signal Type

price Multiplier
price Relative

Payload Value

Some Signals are restricted to certain Integer value or % but for the most part any value can be sent.

See Special Event Signals for more information or refer to the OpenADR 2.0b Profile Specification.


Special Signals

Only SIMPLE-level with a value less than 3 will conform to a predefined relay output strategy (Moderate & High). All other combinations are commonly referred to as “Special” or non OpenADR 2.0a signals although the Pending relay is still used to identify an Event notification.

Receiving Special signals as the final control device, the VEN must be programmed to for it’s desired outcome which may be different from service area to service area. The logic should be established before the Program is rolled out.

The future of 2.0b. Are other countries surpassing the US implementing 2.0b?

What if?

What if a VEN could change its control logic, set point or process variable based a OpenADR signal?

What if the signal could be expanded into the ever growing IOT home automation boom?

What if the VTN was able to send Events based on grid frequency or voltage as well as peak demand?

What if the VEN had the intelligence to adjust facility resources to shed, consume, store or inject energy ?

Dynamic ADR incorporates all that the OpenADR architects envisioned. GRIDlink Technologies is working with Utilities in Thailand, New Zealand and the UK now achieving these advancements using OpenADR 2,0b signals.

 See more …