vita49Reader

VITA 49 file reader

Since R2022b

Description

The vita49Reader object reads and decodes the VMEbus International Trade Association (VITA) 49 packets from the input VITA 49 file or workspace. The object reads both signal data packets and context packets.

Creation

Syntax

vita49ReaderObj = vita49Reader(filename)

vita49ReaderObj = vita49Reader

vita49ReaderObj = vita49Reader(filename,OutputTimestampFormat="datetime")

Description

vita49ReaderObj = vita49Reader(filename) creates a VITA 49 file reader System object™ to read the packets from the input VITA 49 file.

vita49ReaderObj = vita49Reader creates a VITA 49 file reader to read the packets from the workspace.

vita49ReaderObj = vita49Reader(filename,OutputTimestampFormat="datetime") sets the OutputTimestampFormat property to "datetime".

Input Arguments

filename — Name of VITA 49 file

character vector | string scalar

This property is read-only.

Name of a VITA 49 file, including the extension, specified as a character vector or a string scalar. After creating the file, the filename is a read-only property.

Data Types: char | string

Properties

FileName — Name of VITA 49 file

character vector | string scalar

This property is read-only.

Name of VITA 49 file once it is created by the input filename, specified as a character vector or a string scalar.

Data Types: char | string

OutputTimestampFormat — Output format for packet timestamp

"seconds" (default) | "datetime"

Output format for the packet timestamp, specified as "seconds" or "datetime". This value specifies the timestamp of the decoded VITA 49 packet.

Data Types: char | string

PacketsRead — Total number of packets read

integer scalar

This property is read-only.

Total number of packets read, stored as an integer scalar.

Data Types: double

Object Functions

read	Read next VITA 49 packet
reset	Reset VITA 49 file reader to first VITA 49 packet of file

Examples

Read Specified Number of Packets from File

Create a VITA 49 file reader object, specifying the name of a VITA 49 file and an output format for the packet timestamp.

vita49ReaderObj = vita49Reader("VITA49SampleData.bin");
vita49ReaderObj.OutputTimestampFormat = "seconds";

Specify the number of packets to be read from the file.

numpkt = 11;

Read the specified number of packets from the VITA 49 file to the MATLAB® workspace.

[signalDataPacket,contextPacket,contextPacketChangeIndex] = read(vita49ReaderObj,NumPackets=numpkt)

signalDataPacket = struct with fields:
                  PacketType: 1
                    StreamID: 0
                     ClassID: "7C386C0000"
                 PadBitCount: 0
        IntegerTimestampType: "GPS"
       IntegerTimestampValue: 1625215654
     FractionalTimestampType: "real time"
    FractionalTimestampValue: 900000344000
                    RawBytes: [1472x1 uint8]
                   IQSamples: [722x1 double]
                     Trailer: [1x1 struct]

contextPacket=1×10 struct array with fields:
    PacketType
    StreamID
    ClassID
    IntegerTimestampType
    IntegerTimestampValue
    FractionalTimestampType
    FractionalTimestampValue
    RawBytes
    ContextFieldChangeIndicator
    ReferencePointIdentifier
    Bandwidth
    IFReferenceFrequency
    RFFrequency
    RFFrequencyOffset
    IFBandOffset
    ReferenceLevel
    Gain
    OverRangeCount
    SampleRate
    TimestampAdjustment
    TimestampCalibrationTime
    StateAndEventIndicator
    SignalDataPayloadFormat
      ⋮

contextPacketChangeIndex = 1×10

     0     0     0     0     0     0     0     0     0     1

Clear the vita49Reader System object.

clear vita49ReaderObj

Read Specified Number of Packets from Workspace

Create a VITA 49 file reader object without any input arguments.

vita49ReaderObj = vita49Reader;

Load vita49Data.mat into the workspace.

load('vita49Data.mat')

The vita49Data.mat consists of a variable data with 37 VITA 49 packets. Read the VITA 49 packets from the variable data.

[sigDataPackets,contextPackets,contextChangeIdx,commandPackets, ...
      processedlen] = read(vita49ReaderObj, data, "NumPackets",37);

Clear the vita49Reader System object.

clear vita49ReaderObj

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

Code generation is available only when the OutputTimestampFormat property is set to the default value of "seconds".

Version History

Introduced in R2022b

R2023b: Moved to Communications Toolbox from Satellite Communications Toolbox

Previously, vita49Reader required Satellite Communications Toolbox.