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Re: Two-wires RS485 and the driver enable problem

From glen herrmannsfeldt <gah@ugcs.caltech.edu>
Newsgroups comp.arch.embedded
Subject Re: Two-wires RS485 and the driver enable problem
Date 2014-10-13 20:55 +0000
Organization Aioe.org NNTP Server
Message-ID <m1he8s$lsi$1@speranza.aioe.org> (permalink)
References <m1geor$bt4$1@dont-email.me>

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pozzugno <pozzugno@gmail.com> wrote:
> I have a multi-drop two-wires RS485 bus.  One node is the master and all 
> the others are slaves.  The master is the only node that is authorized 
> to initiate a transmission, addressing one slave.  The addressed slave 
> usually answers to the master.
 
> The bus is half-duplex, so every node disables the driver.  Only THE 
> node that transmits data on the bus enables the driver and disables it 
> as soon as it can, just after the last byte.  An interrupt (transmit 
> complete) usually triggers when the last byte is totally shifted out, so 
> the driver can be disabled immediately.

Ethernet has a minimum time between packets that is independent
of most other timing parameters. The suggestion for it is that it
is enough time for the receiver to get the data out of its buffer,
and get ready to receive again. 

-- glen

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Thread

Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-13 13:58 +0200
  Re: Two-wires RS485 and the driver enable problem Wouter van Ooijen <wouter@voti.nl> - 2014-10-13 14:29 +0200
    Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-13 14:38 +0200
      Re: Two-wires RS485 and the driver enable problem Wouter van Ooijen <wouter@voti.nl> - 2014-10-13 15:28 +0200
        Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-13 07:21 -0700
          Re: Two-wires RS485 and the driver enable problem Wouter van Ooijen <wouter@voti.nl> - 2014-10-13 16:46 +0200
            Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-13 08:02 -0700
        Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-13 16:59 +0200
          Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-13 08:08 -0700
            Re: Two-wires RS485 and the driver enable problem pozz <pozzugno@gmail.com> - 2014-10-14 07:48 +0200
              Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-13 23:28 -0700
                Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-14 09:20 +0200
                Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-14 06:09 -0700
              Re: Two-wires RS485 and the driver enable problem David Brown <david.brown@hesbynett.no> - 2014-10-14 10:36 +0200
          Re: Two-wires RS485 and the driver enable problem Wouter van Ooijen <wouter@voti.nl> - 2014-10-13 18:14 +0200
      Re: Two-wires RS485 and the driver enable problem Tim Wescott <seemywebsite@myfooter.really> - 2014-10-13 16:30 -0500
  Re: Two-wires RS485 and the driver enable problem David Brown <david.brown@hesbynett.no> - 2014-10-13 14:47 +0200
    Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-13 14:56 +0200
      Re: Two-wires RS485 and the driver enable problem David Brown <david.brown@hesbynett.no> - 2014-10-13 16:13 +0200
      Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-13 08:06 -0700
        Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-14 08:50 +0200
          Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-14 14:34 -0700
  Re: Two-wires RS485 and the driver enable problem Richard Damon <Richard@Damon-Family.org> - 2014-10-13 09:11 -0400
  Re: Two-wires RS485 and the driver enable problem rickman <gnuarm@gmail.com> - 2014-10-13 10:53 -0400
    Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-13 17:03 +0200
  Re: Two-wires RS485 and the driver enable problem Grant Edwards <invalid@invalid.invalid> - 2014-10-13 15:20 +0000
    Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-16 09:01 +0200
      Re: Two-wires RS485 and the driver enable problem Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-10-16 10:19 +0300
      Re: Two-wires RS485 and the driver enable problem rickman <gnuarm@gmail.com> - 2014-10-16 05:02 -0400
  Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-13 08:17 -0700
    Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-13 08:19 -0700
    Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-14 09:28 +0200
      Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-14 06:09 -0700
        Re: Two-wires RS485 and the driver enable problem rickman <gnuarm@gmail.com> - 2014-10-14 14:28 -0400
    Re: Two-wires RS485 and the driver enable problem rickman <gnuarm@gmail.com> - 2014-10-14 04:36 -0400
  Re: Two-wires RS485 and the driver enable problem Les Cargill <lcargill99@comcast.com> - 2014-10-13 12:35 -0500
    Re: Two-wires RS485 and the driver enable problem langwadt@fonz.dk - 2014-10-13 15:02 -0700
      Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-13 17:36 -0700
        Re: Two-wires RS485 and the driver enable problem Les Cargill <lcargill99@comcast.com> - 2014-10-13 21:53 -0500
          Re: Two-wires RS485 and the driver enable problem Don Y <this@is.not.me.com> - 2014-10-13 20:24 -0700
  Re: Two-wires RS485 and the driver enable problem upsidedown@downunder.com - 2014-10-13 22:02 +0300
    Re: Two-wires RS485 and the driver enable problem Grant Edwards <invalid@invalid.invalid> - 2014-10-13 19:09 +0000
      Re: Two-wires RS485 and the driver enable problem glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-10-13 20:58 +0000
        Re: Two-wires RS485 and the driver enable problem Grant Edwards <invalid@invalid.invalid> - 2014-10-13 21:08 +0000
          Re: Two-wires RS485 and the driver enable problem langwadt@fonz.dk - 2014-10-13 14:40 -0700
    Re: Two-wires RS485 and the driver enable problem Dave Nadler <drn@nadler.com> - 2014-10-14 09:58 -0700
      Re: Two-wires RS485 and the driver enable problem rickman <gnuarm@gmail.com> - 2014-10-14 14:20 -0400
        Re: Two-wires RS485 and the driver enable problem David Brown <david.brown@hesbynett.no> - 2014-10-14 23:35 +0200
          Re: Two-wires RS485 and the driver enable problem rickman <gnuarm@gmail.com> - 2014-10-15 02:00 -0400
            Re: Two-wires RS485 and the driver enable problem David Brown <david.brown@hesbynett.no> - 2014-10-15 09:47 +0200
              Re: Two-wires RS485 and the driver enable problem rickman <gnuarm@gmail.com> - 2014-10-16 01:30 -0400
                Re: Two-wires RS485 and the driver enable problem David Brown <david.brown@hesbynett.no> - 2014-10-16 20:46 +0200
                Re: Two-wires RS485 and the driver enable problem Dave Nadler <drn@nadler.com> - 2014-10-16 12:00 -0700
            Re: Two-wires RS485 and the driver enable problem upsidedown@downunder.com - 2014-10-15 11:01 +0300
            Re: Two-wires RS485 and the driver enable problem Grant Edwards <invalid@invalid.invalid> - 2014-10-15 14:24 +0000
              Re: Two-wires RS485 and the driver enable problem rickman <gnuarm@gmail.com> - 2014-10-16 01:17 -0400
                Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-16 08:36 +0200
                Re: Two-wires RS485 and the driver enable problem rickman <gnuarm@gmail.com> - 2014-10-16 05:05 -0400
                Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-16 12:54 +0200
                Re: Two-wires RS485 and the driver enable problem Grant Edwards <invalid@invalid.invalid> - 2014-10-16 14:16 +0000
    Re: Two-wires RS485 and the driver enable problem upsidedown@downunder.com - 2014-10-15 09:09 +0300
      Re: Two-wires RS485 and the driver enable problem Grant Edwards <invalid@invalid.invalid> - 2014-10-15 14:26 +0000
  Re: Two-wires RS485 and the driver enable problem glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-10-13 20:55 +0000
  Re: Two-wires RS485 and the driver enable problem Tim Wescott <seemywebsite@myfooter.really> - 2014-10-13 16:37 -0500
    Re: Two-wires RS485 and the driver enable problem pozzugno <pozzugno@gmail.com> - 2014-10-14 09:37 +0200
  Re: Two-wires RS485 and the driver enable problem Arlet Ottens <usenet+5@c-scape.nl> - 2014-10-14 20:44 +0200

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