JAI VISCAM 1000 System, Руководство по установке

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Appendix D 49
VISCAM 1000 Systems
8 Appendix D: Ethernet Requirements
The Ethernet media is the key component for data transmission in the VISCAM 1000 system.
In order to ensure a smooth running system, install the Ethernet infrastructure with the following
considerations in mind:
•
Physical cabling - minimum Cat 5E is recommended – in larger systems, Cat 6 or fiber optic cables are
recommended for backbones with high traffic loads. It is strongly recommended that the quality of the
installed Ethernet cabling is verified with a suitable network tester (certifier) such as Fluke Optiview, Fluke
Etherscope, Lantek 6 or similar.
•
Network speed – The minimum speed required is 100 Mbit – though 1000 Mbit (1Gbit) is the optimal speed
and ensures sufficient bandwidth in most applications. In general, assessment of network speed is an
important issue, and should have been taken into consideration in the design phase. The transmission
speed on a local gantry with (for example) 4 EN-Camera units, could very well be based on a 100 Mbit
network topology, which then is linked externally with a 1 Gbit FO (Fiber Optic) uplink to the server
location – see Figure 49
Figure 49. Network cabling example:
•
The actual traffic load that the individual cameras inflict on the network depends heavily on the cameras
current run mode – in a normal operable system, the cameras run in asynchronous mode, which means that
the cameras only grab images when triggered. If the same camera is set to synchronous mode, which is the
mode typically used during alignment and diagnostics procedures, the camera grabs the images with a
speed of approximately 10 images per second (measured on a 1.4 GHz Intel Centrino based laptop) – the
load will now rise to around 30% per camera. Even the drastic increase in network load when using
synchronous mode, will normally not be a problem, since the mode is only applied to the cameras of
interest.
Throughput per lane: Four (4) vehicles per second for a five (5) second burst rate – not indefinitely
sustainable. One vehicle per second sustainable indefinitely.