NED
UME-0111-01
RCDL4K8GE
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4.4 Calculating the Maximum Value of Packet Delay
The maximum value for the packet delay setting can be calculated as below.
In order to achieve the desired frame rate without dropping frames, it is necessary to
set a value smaller than the maximum packet delay.
Payload Size = Width x Height x (No. of Bytes/pixel)
RGB8Packed
:
3 Byte/pixel
No. of packets in 1 frame = Payload Size / (Packet Size-Data Header:36 Bytes)
Transfer time for 1 frame=(Payload Size+No. of packets/frame x Data Header)
/Gigabit Ethernet Transfer Rate (Max 125 Mbyte/s)
Notes:
The maximum Gigabit Ethernet transfer rate may vary depending on the processing
power of your PC and NIC. Allowing some margin, it is recommended to calculate
around 110~120 Mbytes/s.
1 Frame Scan Period = 1 Line Scan Period x Height
1 Frame Time Margin = 1 Frame Scan Period - 1 Frame Transfer Period
Packet Delay Time = 1 Frame Time Margin / No. of packets/frame
Max. Packet delay value = Packet Delay time [ns] x 60 / 1000
e.g. Minimum scan period at 4096 pixels (Width: 4096, Height: 2048, RGB8Packed,
1 Line Scan Period: 200.0us. Packet Size: 4000, Transfer Rate: 120Mbyte/s)
Payload Size
= 25165824 (Bytes/Pixel)
No. of packets/frame
= 6349
Transfer Period for 1 frame = 211620 [us]
1 Frame Scan Period
= 409600 [us]
1 Frame Time Margin
= 197980 [us]
Packet Delay Time
= 31182.9 [ns]
Packet Delay Setting Value =
1871
(Framerate = 2.5 [fps])