Packet Delay; Determining Bandwidth Requirements - FLIR GRASSHOPPER 3 Series Technical Reference

To adjust the packet size:
From the GigE Configurator with your adapter selected, click Open Network Connections to open the Windows
Adapter Properties. Adjust the packet size of your host adapter to ~9000 (the standard jumbo packet size). If your
adapter does not support such a large packet (or MTU) size, then you will experience slightly higher CPU usage.
Packet size for the camera can be adjusted using the FlyCap demo program, the GevSCPSPacketSize
GenICam feature, or the
SCPS. For more information, consult the FlyCapture SDK Help.
Changing the packet size may impact throughput depending on the packet delay setting.

2.4.3.2 Packet Delay

The stream channel packet delay (SCPD) indicates the number of ticks (at the frequency of the Timestamp Tick
Frequency) to insert between each packet. The default packet delay is 400.
The Timestamp Tick Frequency is normally 125,000,000 ticks/second, but can be verified by the the
GevTimestampTickFrequency GenICam feature, or the Timestamp Tick Frequency Bootstrap register
113).
The packet delay acts like a gap between packets during transmission. This delay allows the host to process the
current packet before the arrival of the next one. When you increase the packet delay value from zero, you reduce
the effective bandwidth assigned to the camera and thereby also reduce the possibility of dropped frames.
Increasing the packet delay may require the frame rate to be reduced to meet the available maximum bandwidth.
Achieving a desired frame rate may require decreasing the packet delay.
To adjust the packet delay:
Packet delay for the camera can be adjusted using the FlyCap demo program, the GevSCPD
or the GigE Vision Bootstrap Registers
information, consult the FlyCapture SDK Help.

2.4.3.3 Determining Bandwidth Requirements

The maximum bandwidth available is 125 MB. This includes image data, control data and image resends, which
occur when frames are being dropped. Each image and each packet has a certain amount of overhead that will
2/10/2017
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Note: From the GigE Configurator with your camera selected,
click Discover Maximum Packet Size. This tests the network to
see the maximum size that can be sent and received through all
your network components. Set your camera's and host adapter's
packet size to be less than or equal to this maximum.
GigE Vision Bootstrap Registers
Note: Increasing the packet delay is recommended when
running multiple cameras through an Ethernet switch.
. The FlyCapture SDK also supports configuring the SCPD. For more
Grasshopper
2 Grasshopper3 PGE Installation
. The FlyCapture SDK also supports configuring the
®
3 PGE Technical Reference
(page
GenICam Features,
13