Re: Stops in the motor record

[Guy Jennings <jennings@pop.msd.anl.gov>]

         Reply to:   Re: Stops in the motor record
This may explain a puzzling problem we have seen where the first point in a motor scan is wrong.  I had thought it was a problem with my own code!

Now, all we need is for someone to fix it!!!

Graham Waters wrote:
>Janet Tvedt wrote:
>> >> To users of the motor record:
>> >> This code segment from recMotor.c is causing me some problems.  Stops are >issued
>> when they should not be.  I think this is happening because the axis is >queried
>> before it has started moving and the last move was in the opposite >direction from
>> the current move.
>> >> Has this been a problem for others?  What would you recommend doing to fix it?
>
>I have seen this behavior in the following motor record distribution
>(www.aps.anl.gov/xfd/SoftDist/swBCDA/xfdApp R3.13.0.beta7
>unbuilt.tar.gz)
>
>It has puzzled me but I have no time to investigate the problem, Glad
>I'm
>not the only one to see it.
>
>+---------------------------------------------------------------------+
>|Graham Waters, Control System Eng          Internet: waters@triumf.ca|
>|TRIUMF --- University of British Columbia,    phone: (604)-222-1047  |
>|Vancouver, BC, Canada                           Fax: (604)-222-7307  |
>|http://sunset.triumf.ca/homepage/graham01.html                       |
>+---------------------------------------------------------------------+
>
>RFC822 header
>-----------------------------------
>
>Received: from dns2.anl.gov (dns2.anl.gov [146.139.254.3]) by >pop.msd.anl.gov (8.8.7/8.6.11) with ESMTP id RAA05320 for <jennings@pop.msd.anl.gov>; Thu, 26 >Mar 1998 17:03:42 -0600 (CST)
>Received: from epics (epics.aps.anl.gov [164.54.8.141]) by dns2.anl.gov >(8.8.7/8.6.11) with SMTP id RAA14152; Thu, 26 Mar 1998 17:04:08 -0600 (CST)
>Received: from REG.TRIUMF.CA by epics (SMI-8.6/SMI-SVR4)
>	id QAA16709; Thu, 26 Mar 1998 16:55:06 -0600
>Received: from triumf.ca (edevel6pc.Triumf.CA) by Erich.Triumf.CA (MX V4.0-1
>          VAX) with SMTP; Thu, 26 Mar 1998 14:54:57 PST
>Message-ID: <351ADCFD.5B746353@triumf.ca>
>Date: Thu, 26 Mar 1998 14:55:57 -0800
>From: Graham Waters <waters@triumf.ca>
>Reply-To: waters@triumf.ca
>Organization: TRIUMF
>X-Mailer: Mozilla 4.03 [en] (Win95; I)
>MIME-Version: 1.0
>To: tech-talk@aps.anl.gov
>Subject: Re: Stops in the motor record
>References: <199803261845.LAA14700@kiwi.tuc.noao.edu>
>Content-Transfer-Encoding: 7bit
>Content-Type: text/plain; charset=us-ascii
>Content-Length: 1090
>Status:   >