comp.lang.ada
 help / color / mirror / Atom feed
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: embedded programming for unreliable hardware
Date: Wed, 15 Feb 2006 10:17:16 +0100
Date: 2006-02-15T10:17:17+01:00	[thread overview]
Message-ID: <1ndy2tjefyddo.1a02jjir70zm4.dlg@40tude.net> (raw)
In-Reply-To: nmzIf.1839$JR6.201@newsread3.news.pas.earthlink.net

On Wed, 15 Feb 2006 05:54:27 GMT, Jeffrey R. Carter wrote:

> For actuators, it depends on whether you command to an absolute value or not. If 
> you command to an absolute value ("turn on") then issuing the command twice 
> should ensure that it's performed. If you command a relative change ("toggle 
> power") then you'd need to issue the command, check the result through a sensor, 
> and reissue if it didn't take. Issuing twice will work 99.75% of the time.

Somewhat complementary technique is safe actuators design. Some actuators
have a safe-state command, they perform it automatically if no new command
comes. For example, a lift truck holds on the load by default. If you want
to lift it up, you have to permanently repeat "up", "up", "up"... Should
one command not arrive, no problem.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de



      reply	other threads:[~2006-02-15  9:17 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-02-14 22:03 embedded programming for unreliable hardware tmoran
2006-02-15  5:54 ` Jeffrey R. Carter
2006-02-15  9:17   ` Dmitry A. Kazakov [this message]
replies disabled

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox