Hi >From the ds2409 description: >>>> the coupler maintains a common ground level for the whole network and keeps the inactive segments powered. This simplifies supplying central or local power for additional circuitry and prevents loss of status of parasitically powered devices. It also avoids disrupting communication caused by the parasitic power supply of 1-Wire devices after activating a branch. <<<<
It appears that the ds2409 is designed to help parasitically powered devices doing their job while other branches are accessed. It could mean that each ds2409 branch could be considered totally independant. But after reading the ds2409 datasheet, there is something I don't understand, there is a direct-on main command but no direct-on aux command. Should I understand that everytime a branch is accessed, a reset pulse is sent first? meaning that it is not possible to access other branches while an unpowered conversion? in the other thread, daryl said: >>>>>> I just tried it by adding an unpowered sensor to my net and doing the following... echo 1 > simultaneous/temperature cat 10.*/temperature The result was that it paused to do the conversion on the one unpowered sensor, and all the powered ones came up right away. The unpowered sensor probably tries to do the conversion with all the powered ones, but since the data bus isn't being held high the conversion fails. <<<<<<<<<< I think the explaination of this is that the unpowered device lost its power because of the data line not being held high by the strong pullup. As it totally lost power, it goes into unknown state, and can't respond to new convert commands before being initialized again. So it is true that powered and unpowered should not be mixed only in a branch. In my system, unpowered devices are all in separate branches, and I should be able to make simultaneous conversions. Also, I don't understand how jerry's example works. He triggers the top simultaneous temperature reading. Does this trigger the conversion on all hub branches? ------------------------------------------------------------------------------ The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
