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The CVB GEV Server library stores its configuration data and persistent state in the CVB GEV Server.cfg file.
This file is located in the Common Applications Data folder of your operating system:
{AllUsersProfile}\STEMMER IMAGING\Common Vision Blox
or simply the {CVBDATA} environment variable pointing to:
C:\ProgramData\STEMMER IMAGING\Common Vision Blox
The CVB GEV Server library supports monochrome images with up to 16 bits per pixel and RGB images with up to 8 bits per pixel.
Although the CVB GEV Server can work on every memory layout supported by CVB, certain layouts need to be converted internally.
The transfer buffer expects the pixel data in a linear fashion pixel after pixel without gaps.
For e.g. RGB images this would be RGBRGBRG…
If the image data to be transferred does not resemble that format it has to be copied into that format by the CVB GEV Server.
All this is done automatically but is paid with a sleight performance loss.
Filter Driver vs. Socket Driver
If possible use the filter driver as it minimizes the overhead of the normal Windows IP stack and reduces the CPU load significantly.
Only use the Socket Driver if for example loopback transfer is needed.
On the receiving side larger packet sizes reduce the CPU load.
The same is true for the sender and thus the server side. The larger the packets the fewer packets need to be sent.
This reduces the number of events to be processed and it improves the net transfer rate as fewer header data needs to be sent.
Applications using the CVB GEV Server library need at least full access rights in a firewall for the entire application.
Ports are requested dynamically from the system for streaming data and therefore a simple port rule would not be sufficient.
Per application settings for a local firewall also introduce a significant performance penalty as the firewall still has to touch all the packets to check which is the sending/receiving application.
It is recommended to use a dedicated network card for the image data transfer and disable the firewall for the whole interface.
This imaging network should be physically separated from the normal company or communications network for security and performance reasons.
The CVB GEV Server.cfg file is an XML file.
Near the top of the file is the Log element which contains the LogLevel and LogTarget elements.
Possible log levels are:
0 |
No Logging (default) |
1 |
Log everything (information, warnings and errors) |
2 |
Log only warnings and errors |
4 |
Log only errors |
Possible log targets are:
0 |
Console window (default) |
1 |
File: The generated file will be located in the same directory as the CVB GEV Server.cfg and is named CVB GEV Server.log. New logs are appended to this file. |
To make the identification of several CVB GEV Server instances easier the User ID feature is implemented.
The GigE Vision™ standard states that the value of this feature must be written to persistent memory.
The persistent storage for the CVB GEV Server library is the hard disk.
All settings specific to a CVB GEV Server instance are saved under its Device ID.
If later an instance with the same device ID is opened the stored values are restored automatically.