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by Lui Elle :: Rate this Message:

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hi,
with USB9097 then plug 8 DS1820 and 2 DS2450 i see only 8 x DS1820 ,
if plug only 2 x DS2450 , i see tow DS2450.
if plug only 8 x DS1820 , i see 8 X DS1820
why the DS2450 lost with DS1820 plugged ?
thank you

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Re: (no subject)

by Pascal Baerten :: Rate this Message:

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I guess you are using parasitic power mode for your devices.

The voltage drop on DQ is too important to power the ds2450 while still enough to power ds1820.

Looking at datasheets reveal that the ds2450 require 4.5V as minimum voltage while ds1820 works with voltage as low as 3.0V

My recommendation is to supply 5V on a third wire and ensure that slave have their vcc connected on this wire.

Alternatively look if owfs provide control on active pullup and strong pullup settings that may help to feed more slaves parasistically.

Pascal

2012/1/28 Lui Elle <paspourlongtemps@...>

hi,
with USB9097 then plug 8 DS1820 and 2 DS2450 i see only 8 x DS1820 ,
if plug only 2 x DS2450 , i see tow DS2450.
if plug only 8 x DS1820 , i see 8 X DS1820
why the DS2450 lost with DS1820 plugged ?
thank you

------------------------------------------------------------------------------
Try before you buy = See our experts in action!
The most comprehensive online learning library for Microsoft developers
is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3,
Metro Style Apps, more. Free future releases when you subscribe now!
http://p.sf.net/sfu/learndevnow-dev2
_______________________________________________
Owfs-developers mailing list
Owfs-developers@...
https://lists.sourceforge.net/lists/listinfo/owfs-developers

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