[etherlab-users] how to preserve nvram writing cycles when SDO settings are needed at startup ?

[Sebastien BLANCHET]

Dear Ronaldo,

Indeed the limit of writing cycles for SDO registers depends on the 
manufacturer. Sometimes SDO registers are volatile, sometimes are 
persistant.

For example, on Kollmorgen AKD servo drives, the SDO configuration is 
volatile and then a specific command is required to save it in NVRAM.
On such devices you can use 'stupid' start-up list.

On the other hand on Beckhoff ELxxxx terminals, the SDO configuration is 
always saved in the NVRAM. So it is better to use smart start-up list to 
preserve NVRAM writing cycles.

Your answer was very interesting for me because I did not know 
ecrt_master_sdo_upload and ecrt_master_sdo_download functions.
I will try to use them to implement a smart start-up list.

Indeed I have also written a python script to check automatically the 
SDO configuration, because I may be convenient in other situations.
Interested people can download a copy here:
http://iram.fr/~blanchet/ethercat/ethercat-chkconf/

regards,
---
Sebastien

On 25/07/2014 14:26, ronaldo.mercado at diamond.ac.uk wrote:
> Hello Sebastien,
>
> Version 1.5 of the API has ecrt_master_sdo_upload and ecrt_master_sdo_download.
>
> I haven't looked to see if the implementation is the same as the tool for upload/download but I don't see the limitation to only using ecrt_slave_config_sdoXX.
>
> Your second option is thus flexible enough to emulate the smart start-up list.
>
> I was interested to read your message, because I wasn't aware that there is a limit in the number of times SDO registers can be programmed.
>
> Regards,
>
> Ronaldo
>
>