How to Set Up Streams

This guide walks through defining a stream in streams.json, describing its data blocks, and picking/configuring the right driver for your hardware or network interface.

1. Understand the streams.json structure

APIC uses streams.json to define how data flows between LRUs, simulations, hardware drivers, and network interfaces. Each stream contains a blocks list and a driver configuration:

{
  "streams": {
    "[StreamName]": {
      "blocks": [ ... ],
      "driver": { ... }
    }
  }
}

2. Define the blocks array

Each block describes one data element flowing in or out of the stream:

{
  "raw": "LRU_Seeker.VideoFrame",
  "direction": "in",
  "framePerMS": 10,
  "rawcounterbyte": 4,
  "headerMarker": "534f_2A",
  "model": "modelName"
}

3. Choose and configure a driver

The driver object determines which transport the stream uses. Pick the driver that matches your interface:

Sniffer Driver (network capture)

Captures packets from network interfaces using SnifferDriver. Supports local, remote, or both directions, and optional pcap filters.

"driver": {
  "name": "SnifferDriver",
  "active": true,
  "adapter": "\\Device\\NPF_Loopback",
  "filter": "udp",
  "remoteIP": "127.0.0.1",
  "remotePort": 0,
  "localIP": "127.0.0.1",
  "localPort": 3021,
  "source": "remote",
  "destination": "remote"
}

NI65xx Driver (NIDAQ)

Interfaces with NI DAQ cards, supporting multiple ports, read/write configuration, raw types, and power-up states.

"driver": {
  "name": "NI65xxDriver",
  "active": true,
  "CardType": "MX",
  "DeviceID": 1,
  "PortNum": 2,
  "PowerUpState": "low",
  "RawType": "U",
  "LinesPerPort": 16,
  "Port0": "R",
  "Port1": "W"
}

Socket Drivers (UDP / TCP)

Handles UDP and TCP sockets with multiple IN/OUT blocks, optional header markers, and raw counter bytes.

"driver": {
  "name": "UDPSocketDriver",
  "active": true,
  "remoteIP": "172.30.176.2",
  "remoteIPBind": "172.30.192.1",
  "remotePortBind": 8081,
  "remotePort": 8081,
  "localIP": "172.30.192.1",
  "localPort": 8081
}

Use "name": "TCPSocketDriver" for TCP. remoteIPBind/remotePortBind apply only to TCP and set the local bind used when connecting out. localIP/localPort define where the driver listens.

XDMA Driver (FPGA high-speed streaming)

Handles high-speed FPGA streaming: video frames, frame sync, metadata, and static/dynamic modes.

"driver": {
  "name": "XDMADriver",
  "DeviceGuid": "{74c7e4a9-6d5d-4a70-bc0d-20691dff9e9d}",
  "userBaseAddress": "0x00020000",
  "DDR_BASE": "0x88000000",
  "DeviceIndex": 0,
  "FrameWidth": 640,
  "FrameHeight": 512,
  "BPP": 2,
  "FrameRateUs": 200000,
  "FrameSyncDelayMs": 10,
  "AddMetadata": "Yes",
  "StreamingMode": "Static",
  "SyncSource": "External"
}

CIGI Driver

Implements the CIGI protocol:

"driver": {
  "name": "CIGIDriver",
  "remoteIP": "127.0.0.1",
  "remotePort": 8015,
  "localIP": "",
  "localPort": 8014
}

Serial Driver

Drives a serial port for telemetry, commands, and sensors. Configurable COM port, baud rate, parity, stop bits, and buffer sizes.

"driver": {
  "name": "SerialDriver",
  "file": "c:/data/serialData.txt",
  "comPort": "\\\\.\\COM10",
  "baudRate": 921600,
  "parity": 0,
  "stopBits": 1,
  "byteSize": 8,
  "totalTimeoutConstant": 10,
  "InBufferSize": "auto",
  "OutBufferSize": "4096"
}

The UEI Serial Driver ("name": "UEISerialDriver") uses the same serial settings plus an ip field for the UEI box address.

FFMpeg and GenICam video drivers

Both stream video from a camera. FFMpeg example:

"driver": {
  "name": "FFMPegDriver",
  "cameraName": "Lenovo FHD Webcam",
  "format": "yuvj422p",
  "fps": 30,
  "width": 640,
  "height": 480,
  "bufferSizeMB": 10
}

If cameraName is missing or empty, a list of available connected devices is shown on startup. bufferSizeMB sizes the buffer for incoming frames not yet processed.

GenICam adds hardware trigger support via externalSync (line, activation: RisingEdge/FallingEdge), numOfPreAllocatedBuffers, and waitForFrameTimeout_us (0 = event-driven async mode). Note: setting fps overrides the external sync properties.

Shmem Driver (shared memory)

"driver": {
  "name": "ShmemDriver",
  "filename": "sharememFilename",
  "size": 2048
}

INET Driver (HTTP/SFTP)

"driver": {
  "name": "INETDriver",
  "protocol": "http",
  "IP": "127.0.0.1",
  "port": 30000,
  "URL": "/api/v0/{1}",
  "header": {
    "Content-Type": "application/json",
    "Accept": "text/json",
    "Accept-Language": "en-US",
    "Cache-Control": "no-cache"
  }
}

protocol is "http" or "sftp"; URL can include indexed placeholders. The header object defines custom HTTP headers sent with each request.

GDL90 Driver

Implements the GDL90 protocol for aviation entity display (e.g. ADS-B data between airborne and ground systems):

"driver": {
  "name": "GDL90Driver",
  "active": true,
  "remoteIP": "127.0.0.1",
  "remotePort": 4000,
  "localIP": "",
  "localPort": 4001
}

4. Apply tips and best practices

• Use headerMarker for reliable frame detection in UDP/TCP streams.
• Set rawcounterbyte to detect lost frames.
• Ensure blocks generated by DBSimGenerator match the driver's endian and bit ordering.
• For serial streams, enable overlapping mode for high-throughput.
• Multiple blocks per stream can mix directions (IN/OUT).