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From: doughe@bamboo.TEKTRONIX.COM (Douglas E Helbling;627-2621;46-176;;)
Newsgroups: comp.robotics
Subject: Re: ethernet tethers/connectors for underwater robotics
Keywords: ethernet, in-the-drink
Message-ID: <7934@tekgen.BV.TEK.COM>
Date: 24 Jun 91 19:52:19 GMT
References: <1991Jun24.135758.27527@unhd.unh.edu> <1991Jun20.155520.12703@sagpd1> <1991Jun23.095642.872@jarvis.csri.toronto.edu> <31714@hydra.gatech.EDU>
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Reply-To: doughe@bamboo.cax.tek.com
Organization: CAX Integration Group
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>From: rg@msel.unh.edu (Roger Gonzalez)
....
>Any other alternatives for running ethernet out of something that you
>dip in the drink?  (Opening up the pressure tubes to connect is not an
>option- we've had too many close calls with folding or crimping
>O-rings and watching the AUV slowly sink rather than float on the
>surface)

	This looks like a good application for optical fiber.  You could
	install some fairly off-the-shelf fiber transceivers ($300-600ea)
	at the host (surface control) end as well as internal to your subsurface 
	machine,	and use some variation of a standard fiber male-to-male
	 coupler to bridge the signal through the hull.  That way, a complete cable
	severance would still not render the machine open to seawater.



					Doug Helbling