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From: Mike O'Connor <mike@pineview.net>
To: linux-ppp@vger.kernel.org
Subject: Re: Setup pppd over rs-485 point-to-point
Date: Fri, 17 Mar 2017 03:57:06 +0000	[thread overview]
Message-ID: <5d73678b-598e-ee64-fb0a-949e4f229fe1@pineview.net> (raw)
In-Reply-To: <2d19b2f1-bb0f-9a09-6d40-f05388c66af5@gmail.com>

On 17/03/2017 1:48 PM, Woody Wu wrote:
> Hi,
>
> I want to setup pppd to connect a Linux laptop to an embedded Linux
> device. The Linux box connected to a rs-232 to rs485 converter, then
> the convert connected via a two-wire rs-485 cable to the embedded
> Linux device's rs-485 port.
>
This generally will not work as rs-485 is half duplex, the issue is that
the switching time between transmit and receive will mean loss of data,
how ever RS-422 will work.

> On the otherhand, I can make success with similar commands when two
> devices connected with rs-232.  So I guess, this failure was because
> the rs-485 is half-duplex.  But I searched google, people seemed say
> pppd should work over a point-to-point rs-485 connection.  So I want
> to get help from your experts.
>
I've not done any searches but I can not see how it could ever work. PPP
is a an async meaning it can transmit and receive at any time.
> Thanks in advance.
> -woody 
Mike

  reply	other threads:[~2017-03-17  3:57 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-17  3:18 Setup pppd over rs-485 point-to-point Woody Wu
2017-03-17  3:57 ` Mike O'Connor [this message]
2017-03-17  4:42 ` Woody Wu
2017-03-17  5:49 ` Mike O'Connor
2017-03-17  5:50 ` Woody Wu
2017-03-17 12:05 ` James Carlson
2017-03-17 15:13 ` Michael Richardson
2017-03-19 14:40 ` Woody Wu
2017-03-19 14:43 ` Woody Wu
2017-03-20 11:07 ` James Carlson
2017-03-21  3:16 ` Woody Wu

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