DHTP – The DataHub Transfer Protocol

Technical Brief

The Secure Industrial Protocol

DataHub Transfer Protocol (DHTP) is used by the DataHub®, SkkyHub®, ETK, and connected clients to send and receive data in real time over TCP across a LAN, WAN, or the Internet. Originally built upon HTTP, DHTP also supports SSL and WebSocket protocols. In continuous development for over 20 years, DHTP is open and documented in two parts, as the DataHub APIs and the DataHub Command Set.

DHTP Advantages

SkkyHub and DataHub use DHTP to provide these important IIoT features:

Low Bandwidth & Low Latency: Consumes minimal bandwidth, while functioning with the lowest possible latency
Ability to Scale: Can support hundreds or thousands of interconnected data sources and users
Real-Time: Adds virtually no latency to the data transmission

Intelligent Overload Handling: A broker (DataHub, SkkyHub or ETK) responds appropriately when a data user is unable to keep up with the incoming data rate
Quality of Service: Guarantees consistency of data, preserved through multiple hops

DataHub seemlessly integrates DHTP with protocols native to commonly-used industrial applications, such as OPC, Modbus, ODBC, and MQTT. The ETK integrates OPC UA and Modbus.

Examples

As shown in the above diagram, DHTP may be used for the following connection types:

DataHub to DataHub for tunnelling OPC and other protocols on LANs and WANs, with full DMZ support
DataHub to SkkyHub for OT to IT connections and access to remote locations

ETK to DataHub for on-premise connections and edge processing
ETK to SkkyHub for direct connections to the cloud and web HMI
Custom programs to DataHub, to integrate virtually any application

DHTP Protocol Features

DHTP communications between and among DataHub, SkkyHub, ETK, and their clients meet the following criteria for secure, robust industrial and IIoT data communications:

Closed Firewalls: Keeps all incoming firewall ports closed for both data sources and data users
Interoperable Data Format: Encodes the data so that clients and servers do not need to know each others’ protocols
Daisy Chain Servers: Multiple instances of brokers (DataHub, SkkyHub or ETK) can be connected to support a wide range of collection and distribution architectures

Propagation of Failure Notifications: Each client application can know with certainty if and when a connection anywhere along the data path has been lost, and when it recovers
Simple: Message syntax is simple enough to be implemented even on resource-constrained devices
Streamable: Messages can be concatenated and streamed without requiring intervening acknowledgements. This allows clients and servers to communicate asynchronously, reducing latency and significantly improving throughput

Available Now

DataHub, SkkyHub, and embedded devices with ETK support are ready for the Industrial IoT today. You can download the DataHub, request the ETK, or sign up for a risk-free 30-day trial of the SkkyHub service.

Embedded systems and gateways that support the ETK for making connections to DataHub or SkkyHub include Red Lion, B+B SmartWorx, NetComm, SysLINK, as well as a number of embedded boards.

Skkynet’s extensive customer list covers a wide range of industrial sectors, including aerospace, oil & gas, chemicals, pharma, manufacturing, energy & utilities, food & beverage―in short, virtually any area in automation and control or system integration.