SDK that bridges the gap between data acquisition devices, in an era where incompatibility is the norm

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iDDS Modules for openDAQ

An open-source implementation of iDDS (Instrumentation Data Distribution Service) developed using CycloneDDS (CycloneDDS C++ Binding) for openDAQ.

iDDS is an embedded application protocol for data acquisition and control instruments. It uses Data Distribution Service (DDS), a widely adopted data communications protocol that follows a data-centric model.

Features

• Open-source iDDS wrapper built on top of CycloneDDS
• idds-xml-parser for schema validation, encoding, and decoding of iDDS commands
• Node discovery for automatic detection of connected iDDS devices
• Infrastructure to send and receive commands from other iDDS nodes
• Data streaming support for real-time data exchange
• Interoperability with other iDDS implementations
• Configurable QoS for flexible integration
• Client/Server openDAQ modules to streamline test system development

For details on the idds_wrapper and iDDS topics please refer to idds_wrapper README.

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Folder Structure

.
├── cmake                # CMake scripts
├── CMakeLists.txt       # Top-level CMake file
├── examples             # Examples folder
├── external             # External libraries and dependencies
├── idds_client_module   # Client-side implementation of the openDAQ iDDS module
├── idds_server_module   # Server-side implementation of the openDAQ iDDS module
├── idds_wrapper         # Wrapper code around CycloneDDS
├── idds_xml_parser      # XML parser for the iDDS Command subsystem
├── LICENSE              # License file
└── README.md            # Project documentation

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Build Instructions

By default, these options are enabled:

set(IDDS_ENABLE_EXAMPLE "Enable Examples" ON)
set(IDDS_ENABLE_TESTS   "Enable Tests" ON)

Linux Build Instructions

# On a clean repository:
mkdir build
cd build
cmake ..
cmake --build --parallel

Windows Build Instructions (Visual Studio 2022)

# On a clean repository:
cmake -S . -B build -G "Visual Studio 17 2022" -A x64
cmake --build build

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Running Examples

Running Two iDDS Devices

This example demonstrates the operation of two iDDS devices using the iDDS wrapper.

1. Simple Device Example:
   • Creates an instance of an iDDS device.
2. Complete Device Example:
   • Creates an iDDS device instance.
   • Prints available iDDS devices.
   • Sends a Configuration.GetAttribute command.
   • Subscribes to a channelID.
   • Sends General.StartOperating and General.StopOperating commands.
   • Requires user input between stages.
   • By default, all subscribed channels will be printed.

Example Signal Channels (Implemented in iDDS Wrapper):

• Sine Wave: Channel.1 (Name) - 6445 (ID)
• Saw Tooth Wave: Channel.2 (Name) - 6446 (ID)

Running the Example:

cd build/bin
./idds-simple-device

On another terminal instance:

./idds-complete-device

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iDDS Network and Nodes

Nodes in an iDDS network advertise their presence and nature using periodic advertisement messages every 5 seconds. A network host can support multiple nodes, each identified by a system-wide unique node identifier (e.g., <manufacturer><productType><serialNumber>). Nodes can also have logical identifiers and are referenced in control messages using their unique identifiers.

Wrapper Implementation Details

The iDDS wrapper currently implements three DDS topics:

1. ParameterDataSeries (Domain 2) - Used for data streaming.
2. Message (Domain 0) - Used for sending commands between iDDS devices.
3. AboutNode (Domain 0) - Used for node discovery.

The IDL definition for these topics can be found in:

idds_wrapper/idl/iDDS.idl