VITA 49, VITA 49A and VITA 49.2
Sharing Data With Other Applications

You can recall recordings in *.vita49 format, allowing you to share recordings between the VSA software and other programs that support VITA 49, VITA 49A and VITA 49.2 files. VITA 49 is a packet-based protocol to convey digitized signal data and metadata (or context data) pertaining to different reference points within a radio receiver.

Data Format

Packet Types

Signal Data Packets

Supported Payload Format Types

Context Packets

State and Event Indicators

Other Considerations

Data format

The VSA software supports the VITA 49.2 data format. In the Packet Header (shown below), bit 25 indicates the data format. This bit is set to "0" for data format 49.0 and "1" for data format 49.2.

 

Packet Types

The VSA software supports three types of packets: Signal Data Packet without Stream Identifier, Signal Data Packet with Stream Identifier, and Context Packet. The VSA software ignores the stream identifier in the packets, so all signal data packets in the file will be treated as if they don't have a stream identifier.

  Packet Type Bits (31-28) Supported by VSA Description
  0000 YES Signal Data Packet without Stream Identifier
  0001 YES (Stream Identifier ignored) Signal Data Packet with Stream Identifier
  0010 NO Extension Data Packet without Stream Identifier
  0011 NO Extension Data Packet with Stream Identifier
  0100 YES Context Packet

 

Signal Data Packets

Signal Data Packets (Type 0000 or 0001) are indicated as either Time Data (0) or Spectrum Data (1) by bit 24 of the Data Header. The VSA software will recall data payload in Time Data packets only.

*If bit 26 is set to 1 then the trailer indicator bits will be used by the VSA software (see the State and Event Indicators table for how they are used). Note: If a trailer is present in the signal data packet then any indicator bits there that are enabled will be used instead of the equivalent ones in the context packet.

Supported Payload Format Types

For supported payload format types in VSA, please check the sections below:

 

VITA 49.0 (49/49A) and VITA 49.2 Payload Formats

For VITA 49, VITA 49A and VITA 49.2, payload types are defined in context packets.

Within the context packet (shown below), bit 15 needs to be set to 1.

 

If Signal Data Packet Payload Format exists (bit 15 = 1), we can get detailed info from the Data Packet Payload Format Field (in Context packet).

The VSA software has the following Data Packet Payload Format Field requirements:

 

ODI Payload Format

For ODI, payload type information is taken from the ClassId part in the Data packet. A file is treated as an ODI file if the OUI field ClassId in the Data packets is AXLe = 245CCB or Keysight = 800902 (see ODI ClassId definition below).

The VSA software processes ODI data packets whose fields in the ClassId satisfy the following requirements:

  ODI ClassId Field Value
 

Pad Bit Count

00000

 

Reserved

000

 

OUI

0x245CCB for AXIe-defined formats

0x800902 for Keysight-defined formats

 

Pad Word Count

0000

 

ODI Reserved

00

 

Fixed Value

00

 

Event

00 = none

 

R/C

01 = Complex IQ

 

Data Type

0011 000= 16-bit Signed Fixed Point

0100 000= 32-bit Signed Fixed Point

 

Vector Size

0 0000 0000 0000 for one channel

 

Context Packets

The VSA software looks for information in the Context packet to be able to process and show data correctly. See Table 9.1-1 of the VITA 49 standard to see the full Context/Command Indicator Field (CIF Common Intermediate Format: A video image format using 352 horizontal pixels and 288 vertical lines. The format is adopted in multimedia communication standards.) matrix and bit assignments.

For VITA 49.2, Signal Data Packet Payload Format (Bit 15) needs to be set to 1.

For both VITA 49.2 and ODI, the VSA software acts on CIF 0 fields as described in the following table:

  Bit CIF0 Conditions
 

29

Bandwidth

See Bit 21 Sample Rate.

If set to 1 then the value of the Bandwidth field is used as the maximum span in VSA. Note: A value of 0 is not supported for the Bandwidth field.

 

27

RF Radio Frequency: A generic term for radio-based technologies, operating between the Low Frequency range (30k Hz) and the Extra High Frequency range (300 GHz). Reference Frequency

If set to 1, then use it as the input center in VSA.

Input center = RF Reference Frequency + RF Reference Frequency Offset + IF Band Offset

 

26

RF Reference Frequency Offset

If set to 1, then use in determining the input center in VSA (see RF Reference Frequency).

 

25

IF Band Offset

If set to 1, then include the value of the IF Band Offset field in determining the input center in VSA (see RF Reference Frequency).

 

24

Reference Level

If set to 1, use it in VSA to calculate the input range and scaling factor if it's normalized data.

 

21

Sample Rate

If set to 1, use it directly in VSA.

If set to 0, but if Bandwidth is set to 1, use Bandwidth to make the best guess.

If both Sample Rate and Bandwidth are set to 0, use default value 1 as Sample Rate.

 

16

State/Event Indicators

If set to 1 then use the State/Event Indicators field (see the State and Event Indicators table for how VSA uses each of those bits). Note: If a trailer is present in the signal data packet then any indicator bits there that are enabled will be used instead of the equivalent ones in the context packet.

Changes in context packet fields that affect the Input Center calculation in VSA, Sample Rate, Bandwidth, or scaling of the data are handled as follows:

 

State and Event Indicators

  Indicator Bit Position State/Event Indicator Usage in VSA
 

19

Calibrated Time Indicator

Not currently used

 

18

Valid Data Indicator

If the corresponding enabled bit 30 is 1 and this bit is 0 then a DATA? will be indicated in the traces with a reason indicating that this bit was 0.

Note: This is only supported for the streaming usage in VSA and not when recalling VITA 49 recording files.

 

17

Reference Lock Indicator

If the corresponding enabled bit 29 is 1 and this bit is 0 then the status bar in the VSA application window will indicate an UNLOCKED condition for the frequency reference.

Note: This is only supported for the streaming usage in VSA and not when recalling VITA 49 recording files.

 

16

AGC Automatic Gain Control - System which holds the gain and, accordingly, the output of a receiver substantially constant in spite of input- signal amplitude fluctuations./MGC Indicator

Not currently used

 

15

Detected Signal Indicator

Not currently used

 

14

Spectral Inversion Indicator

If the corresponding enabled bit 26 is 1 and this bit is 1 then the VSA software will conjugate the IQ time domain data to reverse the spectral inversion so that the data when viewed and analyzed in VSA is equivalent to what is at the reference point (since this bit indicates whether the spectrum is inverted relative to the reference point). Users can use the Mirror Frequency functionality in VSA to undo this if desired.

 

13

Over-range Indicator

If the corresponding enabled bit 25 is 1 and this bit is 1 then the VSA software will show the indication as follows: When streaming, the OV (overload) indication will show in the traces. When doing playback from a recalled recording, it will be shown in the Info tab of the Recording dialog.

 

12

Sample Loss Indicator

If the corresponding enabled bit 24 is 1 and this bit is 1 then the VSA software will show a DATA? in the traces with a reason indicating that this bit was 0.

Note: This is only supported for the streaming usage in VSA and not when recalling VITA 49 recording files.

 

Other Considerations

See Also

Supported File Formats