Packet Size And Packet Delay - Hitachi KP-FD500GV Operation Manual

Packet size and Packet delay

1. Packet size
KP-FD500GV/F500GV/FD202GV/F202GV/FD145GV/F145GV/FD140GV/F140GV/FD83GV/F83GV/FD33GV/F33GV transfer
image data in a packet including image data and data header. Since transferred packet number decrease when packet size is
increased, transfer rate can improve.
If packet size is set more than MTU (Maximum Transmission Unit), the camera cannot transfer image data.
2. Packet delay
KP-FD500GV/F500GV/FD202GV/F202GV/FD145GV/F145GV/FD140GV/F140GV/FD83GV/F83GV/FD33GV/F33GV can be
set delay time inter image data packets. Image data transfer rate (or frame rate) decrease when packet delay is increased. This
would prevent image data conflict when multiple camera connection.
Actual delay time by setting packet delay can be calculated as follows.
Payload size = Image width × Image height × Byte number per pixel [Byte]
* Byte number per pixel by pixel format is following;
Byte num
1 Byte
2 Byte
3 Byte
4 Byte
6 Byte
Packet number per frame = Payload size / ( Setting of packet size – Data header size )
* Setting of packet size = 512 to 16076 (configurable)
* Data header size = 36 [Byte]
Data transmission time per frame= ( Payload size + Packet number per frame × Data header size ) / Data transmission rate [second]
* Data transmission rate = 1,000,000,000 [bit per second] = 125,000,000 [Byte per second]
CCD transmission time per frame = Clocks per line × Lines per frame / Pix1el clock [second]
* Values by each model are following;
Model
F(D)500GV
F(D)202GV
F(D)145GV
F(D)140GV
F(D)83GV
F(D)33GV
Inter packet delay time = Setting of packet delay × Packet delay unit [second]
* Setting of packet delay = 10 to 1048575 (configurable)
* Packet delay unit = 10 [nano second] = 10
Total delay time = Packet number per frame × Inter packet delay time [second]
* Total delay time < CCD transmission timer per frame – Data transmission time per frame
Delay time = CCD transmission timer per frame – Data transmission time per frame
Image grabbing time per frame = Data transmission time per frame + Delay time [second]
Frame rate = 1 / Image grabbing time per frame [frame per second]
Pixel format
BayerRG8 / Mono8
YUV422Packed / BayerRG10 / BayerRG12 / Mono10 / Mono12
RGB8Packed / BGR8Packed / YUV422_10Packed / YUV422_12Packed
RGB10V1Packed
RGB12Packed
Clocks per line Lines per frame
1924 [clk] 2050 [line]
1920 [clk] 1220 [line]
1792 [clk] 1024 [line]
1792 [clk] 1024 [line]
1270 [clk] 768 [line]
780 [clk] 490 [line]
-8
[second]
Pixel clock CCD transmission time per frame
64.516 [MHz] 0.061135 [second]
72.115 [MHz] 0.061135 [second]
57.692 [MHz] 0.061135 [second]
57.692 [MHz] 0.031807 [second]
37.037 [MHz] 0.026335 [second]
37.037[MHz] 0.010319 [second]
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