Notifications
A key aspect of the design for external interfaces for Market Participants is to provide a simplified variant of the OASIS WS-Notifications standard for the definition of an ERCOT Notification interface. Each Market Participant using the external interface would be required to provide a listener interface for the receipt of notification messages, compliant with the interface provided by ERCOT.
Interfaces Provided
The interfaces provided are based upon the WS-Notifications specification, although for use by ERCOT the interface has been simplified and augmented to fill one gap in the WS-Notification specification. For the purposes of use by Market Participants, there is only one interfaces of interest that is implemented by a Market Participant listener; this is the 'Notify' interface.
The 'Notify' interface is used as a means to asynchronously receive information by Market Participants from ERCOT. Specific examples of this information include:
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Notices
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Alerts
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BidSet acceptance or error reporting
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Awards
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Obligations
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Startup/Shutdown Instructions
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Outages
The following sequence diagram describes the typical/potential set of information exchanges related to Notifications. The actual flows would be different based on the type of notification:
Interfaces Required
The contents of the any structure would be wrapped using the ResponseMessage structure defined in section 2.1.4, as this would allow necessary security information to be passed in a uniform manner. The following table describes the contents of the Notify message.
| Message Element | Value |
|---|---|
| NotificationMessage/Message/any | One or more messages as defined using ERCOT common message structure |
The following table describes the contents of the Acknowledge message.
| Message Element | Value |
|---|---|
| ReplyCode | OK or ERROR |
| TimeStamp | Current time string |
Message Specifications
The WS-Notifications specification identifies a single message structure for notification messages. The payload that is to be delivered by the notification message is represented by the 'any' element in the following message structure, loosely coupling the definition of the payload from the definition of the container message structure defined by WS-Notifications thereby allowing WS-Notifications to be used with any XML data structure. ERCOT uses the SubscriptionReference, Topic and ProducerReference are not used.
The payloads for NotificationMessages are > ALWAYS conveyed using the common message structure (e.g. Message, RequestMessage, or ResponseMessage) as defined in the Services Organization section serving as the 'any' sub-structure in the NotificationMessage structure.
ERCOT uses a variant of WS-Notifications, where an 'Acknowledge' message is sent to acknowledge the receipt of a notification. The WSDL and XSD provided by ERCOT are also simplified to eliminate definitions for interfaces and structures not used by ERCOT. These are described in the appendix.
ERCOT will allow a Market Participant to specify up to two URLs. ERCOT will send notifications to port 443 of the specified URL using an HTTPS connection. ERCOT will sign the SOAP message, where the signature can be verified using the ERCOT public key. This will verify that the notification was sent by ERCOT and was not altered. The 'Acknowledge' message does not need to be signed.
Confirmed and Unconfirmed Trades
DAM Ancillary Service Offer Insufficiency Report
End of Adjustment Period Results