Allocating Bandwidth; Packet Size - FLIR GRASSHOPPER 3 Series Technical Reference

Dynamic (DHCP)—Both the camera and the adapter are set to automatically obtain an IP address. This
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means that the IP address will dynamically change (within a range) every time the camera or computer is
restarted. It may take up to one minute for the IP address to resolve and the camera to enumerate.
Default (LLA)—Both the camera and the adapter use a default IP address from the link-local address block
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169.254.x.x.
The camera assigns its current IP address in the following sequence:
1. Persistent—Uses the defined IP address. If not available, then;
2. DHCP—Attempts to find a dynamic IP address. If not available, then;
3. LLA—Uses the default IP address.
The GigE Configurator can automatically force an IP address refresh. This detects the IP address of the Network
Interface card and automatically sets the camera's IP address relative to the card.
The FlyCap program can be used to test your camera settings and verify operation. From the camera selection
window, you can also automatically force an IP address refresh.
To open the GigE Configurator:
Start Menu > All Programs > Point Grey FlyCapture2 SDK > Utilities > GigEConfigurator
For more information, refer to the online Help file included with the tool.
2.4.3

Allocating Bandwidth

The User Datagram Protocol (UDP) used by the GigE Vision standard provides no guaranteed transmission or
fixed timing mechanism. Therefore, bandwidth must be managed by adjusting packet size and packet delay,
based on desired resolution and frame rate.

2.4.3.1 Packet Size

The stream channel packet size (SCPS) sets the size, in bytes, of the packet to be sent out by the camera. IP,
UDP and GVSP headers are included in this size. The default packet size is 1400 bytes.
Packet size influences the number of interrupts generated which affects CPU usage. The larger the packet size,
the fewer the interrupts for the same amount of data. To minimize CPU usage, increase the packet size.
The upper limit depends on your host adapter, your Ethernet switches (if used), and the camera.
2/10/2017
©2013-2017
FLIR Integrated Imaging
Solutions Inc. All rights reserved.
Figure 2.1: GigE Configurator
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2 Grasshopper3 PGE Installation
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