Re: Record TIME field taken from another record's VAL

[Torsten Bögershausen via Tech-talk <tech-talk at aps.anl.gov>]

Hej Karel,

Having examples was so far the most helpful thing that we have.
What do you think/suggest is missing ?
BR
/Torsten


On 2026-02-16 09:29, Majer Karel wrote:
> Hello Torsten,
>
> Thanks for your answer.
> I think we can handle the the PTP synchronization.
> I'm interested in twincat-ads driver which I wasn't aware of. Is there 
> any documentation on it besides the included examples?
> Thanks,
>
> Karel
> ------------------------------------------------------------------------
> *From:* Torsten Bögershausen <tboegi at edom.se>
> *Sent:* Friday, February 6, 2026 5:26 PM
> *To:* Majer Karel <Karel.Majer at eli-beams.eu>; tech-talk at aps.anl.gov 
> <tech-talk at aps.anl.gov>; tboegi at telia.com <tboegi at telia.com>
> *Subject:* Re: Record TIME field taken from another record's VAL
> I think that there are 2 questions:
> a) can I synchronize TwinCAT with PTP ?
> b) can I trasnport timestamps over ADS ?
> Yes.
> <https://urldefense.us/v3/__https://infosys.beckhoff.com/english.php?content=..*content*1033*__;Ly8v!!G_uCfscf7eWS!eDeVmuN0Z6xfhFMcdc8D6FFkLA0mFmZP65kdVMx0uQjOAdTZbHiVX-3gnmcZ5FAq8pc2z8nEX8kXEg-Uktk$  
> tc3_ads_intro/115883019.html&id= <https://urldefense.us/v3/__https://infosys.beckhoff.com/__;!!G_uCfscf7eWS!eDeVmuN0Z6xfhFMcdc8D6FFkLA0mFmZP65kdVMx0uQjOAdTZbHiVX-3gnmcZ5FAq8pc2z8nEX8kXdFGetRU$  
> english.php?content=../content/1033/tc3_ads_intro/115883019.html&id=>>
> c) Is there an EPICS driver that support it ?
> Yes:
> https://urldefense.us/v3/__https://github.com/epics-modules/twincat-ads/__;!!G_uCfscf7eWS!eDeVmuN0Z6xfhFMcdc8D6FFkLA0mFmZP65kdVMx0uQjOAdTZbHiVX-3gnmcZ5FAq8pc2z8nEX8kXg8Sfda0$  <https://urldefense.us/v3/__https://github.com/epics-__;!!G_uCfscf7eWS!eDeVmuN0Z6xfhFMcdc8D6FFkLA0mFmZP65kdVMx0uQjOAdTZbHiVX-3gnmcZ5FAq8pc2z8nEX8kXqxw7EU8$  
> modules/twincat-ads/>
> But back to a)
> TwinCAT has different clocks.
> You can synchronize the TwinCAT time (TcTime ??) with NTP.
>
> If you need PTP, then you can synchronize the distributed clock
> ("DC") with PTP.
>
> All details are tooooo long to describe here.
> If you want more details, I am happy to set up
> a video meeting.
>
> BR
> /Torsten
>
>
> On 2026-02-06 15:50, Majer Karel via Tech-talk wrote:
> > Hello,
> >
> > We have a number of Beckhoff PLCs installed and we are using ADS device 
> > support (https://urldefense.us/v3/__https://epics.cosylab.com/documentation/adsDriver/index.html__;!!G_uCfscf7eWS!eDeVmuN0Z6xfhFMcdc8D6FFkLA0mFmZP65kdVMx0uQjOAdTZbHiVX-3gnmcZ5FAq8pc2z8nEX8kXwTVRLS0$ 
> > <https://urldefense.us/v3/__https://epics.cosylab.com/documentation/
> > adsDriver/index.html__;!!G_uCfscf7eWS!euLXnna7-qCt-D3EjV5-bjzosTfKt- 
> > sd4lVcov9BLro2tBUjLRx-ed8iuDCVso9vUKL04d9SoJjsUQ8dHHIoBcTCJ3EHAw$>) to 
> > talk to them. We have considered synchronizing them with PTP and 
> > timestamping PVs with PTP timestamps from the PLC, but it's not clear 
> > how to do that of if it's even possible.
> > The ADS protocol does not carry data timestamp (https:// 
> > infosys.beckhoff.com/english.php?content=../content/1033/ 
> > tcinfosys3/11291871243.html&id= <https://urldefense.us/v3/__https://
> > infosys.beckhoff.com/english.php? 
> > content=..*content*1033*tcinfosys3*11291871243.html&id=__;Ly8vLw!! 
> > G_uCfscf7eWS!euLXnna7-qCt-D3EjV5-bjzosTfKt-sd4lVcov9BLro2tBUjLRx- 
> > ed8iuDCVso9vUKL04d9SoJjsUQ8dHHIoBcR89fZiHg$>) and the device support 
> > documentation doesn't mention possibility of using TSE field to obtain 
> > hardware timestamp.
> > My idea was to convert PTP timestamp to double matching EPICS time 
> > format, publish it into ai record and use its VAL to set TIME fields of 
> > other records published by the ADS IOC. I found some tech talk on Soft 
> > Timestamp device support, but I understand it reads from other record's 
> > TIME field. Is there a way to use ai VAL field to set TIME of other records?
> > Thanks,
> >
> > Karel Majer
> >
> > *Karel Majer | Senior software developer*
> > Phone: +420 266 051 514
> > E-mail: karel.majer at eli-beams.eu
> >
> >
> >        
> >
> > *ELI Beamlines Facility|The Extreme Light Infrastructure ERIC*
> > Za Radnicí 835, 252 41 Dolní Břežany, The Czech Republic
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