Dredge plant data are transmitted to the DQM Center in real time through the DQM Web Service. Each dredge plant is provisioned with its own connection information, and the contractor's onboard system sends data in the specified format at a set cadence using one of the supported protocols.
The default and recommended choice for virtually all new implementations. The SDK handles connection management, TLS, authentication, retries, and SAS token generation automatically. Available for C#/.NET, Java, Python, Node.js, C, and embedded C.
Use only if your environment cannot host an SDK runtime. Each message opens a new TLS connection, making it the simplest protocol to implement from scratch but the least efficient for high-frequency transmissions.
Use only if the SDK is not an option and you need a persistent connection. This approach requires you to manually generate, manage, and renew SAS tokens for authentication. Higher implementation complexity.
Hopper Data are transmitted in XML format. Each message should be a single XML document.
Pipeline Data are transmitted in JSON format. Each message should be a single JSON object.
Mechanical Data are transmitted in JSON format. Each message should be a single JSON object.
Scow Data are transmitted in XML format. Each message should be a single XML document.
All events: 6 to 12 seconds
All events: 6 to 12 seconds
Time Interval Events: 1 minute
Dig/Dump Events: a data point must be recorded within 1 second of occurrence.
Loading/Sailing/Offloading/Idle: 1 minute
Open Water Placement: a data point within 1 second of the hull status going from closed to open, and again within 1 second of it going from open to closed. Between those events, 6–12 seconds at a consistent interval.
The contractor acquires, installs and maintains whatever hardware and software reliable internet connectivity requires. The connection has to support real-time transmission and carry enough bandwidth to clear a backlog once an outage ends — a link that is only just fast enough in normal running will never catch up.
If connectivity is lost, the web service is unavailable, or data cannot be transmitted for any other reason, unsent data are queued and transmitted immediately once the connection is restored. Send the oldest data in the queue first and keep going until real-time transmission resumes.
Failure to transmit within these timeframes may be treated as non-compliance, and may result in the plant’s DQM certification being revoked.
Scow data transmission must be fully automated end to end — no step in it may wait on a person. A contractor may transmit directly from the scow, or via a shore-based relay.
Where a relay is used, both legs are bounded:
Every plant carries an easily accessible visual display that shows, in real time, the raw parameters the system is collecting — in the same units as the data being submitted to DQM. Reading the display and reading the transmitted data should be the same exercise.
Where a reported parameter is calculated from more than one sensor, the display must also show the individual sensor values as they are used in the equation, not just the result. That is what makes it possible to tell a bad sensor from a bad calculation without taking the system apart.
Data will be logged locally onboard the dredge plant as a backup of transmitted data. An archive of all data sent to the DQM Center in the format that it was originally collected and transmitted must be maintained.
This archive will be preserved by the contractor for a minimum of one year past the end of the dredging contract. The DQM Center or USACE may require, at no increase in the contract price, that the contractor provide a copy of these data covering specified time periods.
Microsoft's overview of IoT Hub architecture, features, and capabilities.
Landing page for all Azure IoT Hub Device SDKs — C#, Java, Python, Node.js, C, and embedded C.
How to communicate with IoT Hub using the MQTT protocol directly (for non-SDK implementations).
IoT Hub communication protocols including HTTPS direct device-to-cloud messaging.
For onboarding, credentials, test devices, plant type assignment, or payload schemas — contact the USACE National DQM Center.
