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  OpenADR 2.0b Message Schema Reference Guide
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DEFINITION
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The OpenADR 2.0b Message Schema Reference Guide is a standardized XML-based
specification defining the structure, syntax, and semantics of messages exchanged
between energy service providers (e.g., utilities, aggregators) and grid-interactive
end devices (e.g., HVAC systems, battery storage) to enable automated demand
response. It ensures interoperability across vendors and domains by prescribing
strict schema definitions for event notifications, opt-in/opt-out signals, reports,
and responses. The '2.0b' revision refines earlier OpenADR 2.0a specifications with
enhanced security, reporting flexibility, and support for complex event profiles.

OVERVIEW
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OpenADR 2.0b is an implementation profile of the Open Automated Demand Response
standard developed under the California Energy Commission’s (CEC) auspices and
maintained by the OpenADR Alliance. It leverages XML Schema Definition (XSD) files to
formally constrain message content—including <oadrDistributeEvent>,
<oadrRegisterReport>, <oadrReportRequest>, and <oadrCreatedEvent>—ensuring
consistent parsing and validation across heterogeneous systems. Security is enforced
via WS-Security (with X.509 certificates) and optional SAML-based authentication,
while time synchronization relies on ISO 8601 timestamps and UTC alignment to prevent
misaligned event execution. The schema supports hierarchical event structures (e.g.,
nested intervals with ramp rates, multiple targets), multi-party coordination (via
vtnID/virtual top node and venID/virtual end node identifiers), and bidirectional
communication for status feedback and telemetry reporting. Practically, it enables
real-time grid balancing, dynamic pricing integration, and resilience-oriented load
shedding during emergencies—serving as the foundational messaging layer for modern
transactive energy systems and ASHRAE Guideline 36-compliant building automation.

KEY COMPONENTS
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1. XML Schema Definitions (XSD)
2. Message Types (e.g., oadrDistributeEvent, oadrCreatedEvent)
3. Security Headers (WS-Security + X.509/SAML)

APPLICATIONS
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  - Utility-initiated demand response events
  - Building-level load curtailment automation
  - Distributed energy resource (DER) coordination and telemetry reporting

RELATED CONCEPTS
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  - Demand Response (DR)
  - Web Services (SOAP/WSDL)
  - IEC 61850-7-420 (DER communication profiles)

REFERENCES
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OpenADR 2.0b Implementation Profile Specification (https://www.openadr.org/sites/default/files/documents/OpenADR%202.0b%20Implementation%20Profile%20Specification.pdf)
OpenADR Alliance Technical Specifications Archive (https://www.openadr.org/technical-specifications)
NISTIR 7943: Interoperability Framework for Smart Grid Systems (https://doi.org/10.6028/NIST.IR.7943)

TAGS
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demand-response, smart-grid, xml-schema