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The UKHA-ARCHIVE IS CEASING OPERATIONS 31 DEC 2024


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Re: Serial Protocol Capture...


  • To: ukha_d@xxxxxxx
  • Subject: Re: Serial Protocol Capture...
  • From: "David Buckley" <db@xxxxxxx>
  • Date: Mon, 05 May 2003 23:14:34 -0000
  • Mailing-list: list ukha_d@xxxxxxx; contact ukha_d-owner@xxxxxxx
  • Reply-to: ukha_d@xxxxxxx

--- In ukha_d@xxxxxxx, "Dave Mclaughlin" <dave@v...> wrote:
> RS485 is master/slave based so will always be a polling based
system.
>
> Without using the Entech Taiwan software it will be harder but not
impossible to work out which transmission is the master... This is
because you will only have 1 receive port for the RS485 connection to
monitor the link and not 2 as you would with RS232..
>
> Hope that makes sense?

Indeed it does.

Could get a probe on the driver enable pin RS485 driver chip of the
panel and route it through to CTS or some other line if the monitor
can record line activity, like the ancient HP protocol analysers
did.  The at least you'd know when the master was talking.

And despite the fact that panels have internal modems that are
v.slow, I reckon you'll be on 9600.  A scope would let you know for
sure, narrowest pulse widtyh plus a bit of maths...

David.




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