VITA 49 Stream

The VSA Software supports capturing streams of live VITA 49 data with Direct Data Connectivity Option 89601101C. VSA supports direct capture of contiguous streams of VITA 49 data; however, it is recommended to use fixed length segmented capture for higher data rates.

VITA 49 Streaming Using Fixed Length Segmented Capture

Fixed length segmented capture is supported as a way to capture VITA 49 streams when the data rates are high such that a long contiguous capture of a portion of the stream is not possible. Using segmented capture in this scenario allows the user to capture multiple segments from the overall stream where there may be gaps in time between the segments but the data is contiguous within a segment.

While fixed length segmented capture may not be able to give gap-free capture over a long time length, it can allow for gap-free capture within a short time length and capturing the next segment as soon as possible, thus capturing a fair amount of the overall stream even though it can't capture all of it in a gap-free way. The length of each segment is determined by the measurement setup in VSA at the time the measurement in VSA is started.

The maximum data rate for VITA 49 streams consumed by the VSA depends on several factors, including measurement complexity, network equipment speed, VITA 49 stream configuration, and computer performance. Testing has demonstrated that a 90-frame (1.2 MSamples of IQ data) DVB-S2X 256 APSK signal at 200 MSymbols/sec with a Data Item Size (bit depth) of 16 can be measured at bit rates up to 13 Gbps using jumbo packets. Higher rates may be achievable under certain conditions.

Follow these steps to configure VITA 49 streaming with fixed length segmented capture:

In the Instrument Manager (Utilities > Hardware > Instrument Manager), click the Add New Instrument (+) button to open the Add/Edit New Instrument Address dialog.
Click Custom LAN Local Area Network: A communications network that serves users within a local geographical area, typically over distances of around 100m. Wireless LANs use wireless communicaitons to network devices so there is no need for data cabling. and select Vita49 from the Custom Model drop-down menu.
Enter an IP address of this computer and a port to be used.
Point the stream generator to this IP Internet Protocol: A set of instructions defining how information is handled as it travels between systems across the Internet. address and port number as well.
Use this instrument in a VSA hardware configuration and make it the active configuration. The VSA software will open a UDP listener for this address and port when the hardware configuration is connected to a VSA instrument.
Configure Fixed length segmented capture (Input > Capture > Segment Type = Fixed)