Re: [Xml1-wire-devel] New hub design, request for input

[Jac K. <j.k...@th...>]

On Thu, 18 Jan 2001, Bruce Boyes wrote:

> One thing we have been tipped off by Dallas about is that if you short an
> active branch on the 2409 it will hang the network and the 2409 can't
> recover except by power cycling. This is a bug in the 2409 design which
> isn't likely to change soon.

That's the end of my access control design. One can't rely on users to
slot their iButtons into the reader (the one with led) without causing a
short every now and then. Back to the drawing board :-(

> So we are pondering a watchdog which would power cycle the 2409. When the
> 2409 is power  cycled it disabled both branches.

What about a watchdog that resets the 2409 whenever the active branch is
short? If the one-wire signal level stays below a threshold for over 1
second just reset the part. This way there would be no need for almost
continues one-wire activity.

Regards,

Jac

--
 Jac Kersing            Technical Consultant   The-Box Development
 j.k...@th...                         http://www.the-box.com