[etherlab-users] Domain offset overlap

[Dave Page]

Hi,

     Sorry, I misinterpreted your message.

     ecrt_slave_config_reg_pdo_entry can produce apparently overlapping 
offsets when the PDO data is not on even bit boundaries (not divisible 
by 8).

     You may wish to use the unsigned int *bit_position argument to 
discover the bit offsets of your data.

         Best regards - Dave

On 09-Apr-14 15:49, Steve Hartmann wrote:
> Hi Dave,
>
> Thanks for the reply.  I am not using TwinCAT at all.  Also, please 
> forgive my ignorance, but what is the "LRW command".
>
> I'm not sure how to deal with this with the etherlab stack.  If it 
> give me a domain offset of 3 for two different slices (one input and 
> one output), how do I deal with this overlapped data?
>
> Thanks,
>
> Steven
>
>
> From: Dave Page <dave.page at gleeble.com <mailto:dave.page at gleeble.com>>
> Date: Wednesday, April 9, 2014 2:45 PM
> To: Etherlab Users <etherlab-users at etherlab.org 
> <mailto:etherlab-users at etherlab.org>>
> Subject: Re: [etherlab-users] Domain offset overlap
>
>
>     In order to reduce process data size, TwinCAT overlaps the RxPDO 
> and TxPDO for each module, then uses the LRW command to effect the 
> transfer. So, I believe what you're seeing is normal.
>
>         Best regards - Dave Page
>
> On 09-Apr-14 15:41, etherlab-users-request at etherlab.org wrote:
>> Message: 1
>> Date: Wed, 9 Apr 2014 19:41:29 +0000
>> From: Steve Hartmann<shartmann at militho.com>
>> To: Etherlab Users<etherlab-users at etherlab.org>
>> Subject: [etherlab-users] Domain offset overlap
>> Message-ID:<CF6B0C97.F827%shartmann at militho.com>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Hi all,
>>
>> I have written some code to parse the generated XML file from "ethercat xml" and use that to configure the ethercat stack.  The problem I am having is the output from ecrt_slave_config_ret_pdo_entry produces overlapped offsets.  I also tried using ecrt_slave_config_reg_pdo_entry_pos with the same results.  This is a very simple test rig that has one each of DO, DI, AO, and AI slices - all beckhoff.  I have attached a file which includes the generated XML file, the code in question, and the log output.  Does anyone know what I am doing wrong?
>>
>> Best regards,
>>
>> Steven Hartmann
>
>
> -- 
> ------------------------------------------------------------------------
> David Page, Chief Embedded Architect
> Dynamic Systems Inc.
> PO Box 1234
> Poestenkill, NY 12140
> Telephone: +1 (518) 283-5350 | Fax: +1 (518) 283-3160 |


-- 
------------------------------------------------------------------------
David Page, Chief Embedded Architect
Dynamic Systems Inc.
PO Box 1234
Poestenkill, NY 12140
Telephone: +1 (518) 283-5350 | Fax: +1 (518) 283-3160 |
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