MATRIX VISION - mvBlueCOUGAR-X/-XD Technical Documentation
Optimizing the bandwidth

Calculating the needed bandwidth

In some applications, for example, when multiple cameras share a single network path, you have to keep the bandwidth in mind.

You can calculate the needed bandwidth with the following formula:

Network traffic calculator
  Extended block ID (GEV 2.x)
Image width (pixels):
Image height (pixels):
Bytes per pixel:
Network MTU (max. value of the device with the smallest MTU):
Number of payload packets "on-wire": packets
Network traffic: bytes "on-wire"
Theoretical max. frame rate (at Dual Gigabit Ethernet): fps
Theoretical max. frame rate (at Gigabit Ethernet): fps
Theoretical max. frame rate (at 100 MBit): fps
  

Note
Within a GigE network you have a bandwidth of 125 MByte/s; a 100 MBit network has 12.5 MByte/s. The result of this formula is a rough guideline only. Some additional bandwidth is needed by the communication protocol and some other non GigE Vision related network traffic. Apart from that not every network controller can cope with a full 1 GBit/s stream of data, thus "real" results may vary.

Limiting the bandwidth of the imaging device

It is possible to limit the used bandwidth like the following way:

Since
Firmware version 2.25.0
  1. In "Setting -> Base -> Camera -> GenICam -> Device Control -> Device Link Selector" set property "Device Link Throughput Limit Mode" to "On".
  2. Now, you can set the bandwidth with "Device Link Throughput Limit" to your desired bandwidth in bits per second

    Figure 1: wxPropView - Setting Device Link Throughput Limit


Since
Firmware version < 2.25.0
  1. In "Setting -> Base -> Camera -> GenICam -> Transport Layer Control -> Gev Stream Channel Selector" set property "mv Gev SCBW Control" to "mvGevSCBW".

    Figure 2: wxPropView - Setting mvGevSCBW to mvGevSCBWControl


  2. Now, you can set the bandwidth with "mvGevSCBW". E.g. 10000 for 10 MB.
    According to the image size and acquisition settings, the frame rate will be adjusted.

    Figure 3: wxPropView - Setting bandwidth size

In contrast to this smart bandwidth control mechanism of mvBlueCOUGAR-X cameras, with other cameras you have to know and optimize the Inter-Packet Delay of the camera to avoid congestion in the switch (the loss of packages is an indicator of congestion). You can get the Inter-Packet Delay with following calculator:

Inter-Packet Delay calculator
  Extended block ID (GEV 2.x)
GevSCPS (bytes):
PayloadSize (bytes):
Frames (per second):
Overall bandwidth (bytes):
GevTimestampTickFrequency (Hz):
GevSCPD: