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cable length, latency and hub
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Please be positive and constructive with your questions and comments.

cable length, latency and hub

by yoshco on Sat May 10, 2008 4:11 am

hi, before ordering 8 shields. couple of questions:
1. latency - i understand the the data rate hardly taxes the Ethernet spec but is there any data on the latency the network introduce between the arduino and the client? i'll be working in a performance environment with analogue sensor input. latency is important
.
2. length - Ethernet can operate up and above 100m, can i accept the shield to operate at those ranges? i imagine it will be better to supply external power to the arduino, correct?

3. hub - i want each of the 8 arduinos to connect indevidualy to a client via a hub\switcher, does anyone have assumptions (or real world experience) about hub latency and network topology.

thank you ladyada and forum contributors for the inspirational work, keep it going.

first post

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by adafruit on Sat May 10, 2008 1:32 pm

1. theres initial latency for settingup and tearing down a connection but once its been made it should be pretty good. depends on how many routers it has to go thru, of course

2. i think you mean "expect" and thats strongly dependent on your hub. you will need to experiment

in general, these things depend so much on your environment that you will have difficulty getting real numbers unless you 'actually try it'

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by yoshco on Sun May 11, 2008 7:36 am

thnx for the replay, i guess i'll have to check myself...

some more info
http://www.eix.co.uk/Articles/Ethernet/WWarticle.htm

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Location: tlv

Please be positive and constructive with your questions and comments.