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

[Majer Karel via Tech-talk <tech-talk at aps.anl.gov>]

Hi Torsten,

Thank you, this makes the impact of the settings clearer.

Best regards,

Karel

---

From: Torsten Bögershausen <tboegi at edom.se>
Sent: Monday, February 23, 2026 5:56 PM
To: Majer Karel <Karel.Majer at eli-beams.eu>; tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>; tboegi at edom.se <tboegi at edom.se>
Subject: Re: Record TIME field taken from another record's VAL

 

Hej Karel,
here is more light from testing:

Having a longin with
ADSPORT=852/TIMEBASE=PLC/T_DLY_MS=500/TS_MS=200/GVL_PILS.stEL5101CounterValue.nvalue?

... and running camonitor gives, when I move the motor 1 mm:

LabS-MCAG:MC-MCU-1006:EncoderRaw 2026-02-23 17:37:26.395846 4724
LabS-MCAG:MC-MCU-1006:EncoderRaw 2026-02-23 17:37:34.616832 4711
LabS-MCAG:MC-MCU-1006:EncoderRaw 2026-02-23 17:37:34.816508 4690

While pyadsmonitor uses something corresponding to
T_DLY_MS=1/TS_MS=1/
(No, it doesn't use EPICS. I am talking about the parameters for
the notifications, which both epics/twincat-ads and
python/adsmonitor use. See
https://gitlab.esss.lu.se/mcag/sources/pyads-monitor


stEL5101CounterValue.nvalue         2026-02-23 17:37:34.478 4723
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.518 4722
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.538 4721
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.538 4720
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.566 4719
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.567 4717
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.568 4716
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.579 4715
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.587 4713
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.617 4711
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.617 4710
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.618 4708
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.628 4706
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.638 4705
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.666 4703
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.667 4702
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.668 4700
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.677 4699
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.688 4698
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.717 4696
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.717 4695
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.718 4694
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.728 4693
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.738 4692
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.818 4691
stEL5101CounterValue.nvalue         2026-02-23 17:37:34.818 4690


I hope that this explains things a little bit more ?
/Torsten


On 2026-02-19 10:14, Torsten Bögershausen via Tech-talk wrote:
> Hej Karel,
>
> for a second we may need to imagine, how the "notifications" may work:
> The client (EPICS) will ask for a notificaton for each PLC variable
> we want to monitor.
> Now the PLC needs to assemble these notification messages.
> Several notifications may be bundled into one message,
> that goes over the wire. Especially when they share the same timestamp.
> The ADS library inside the IOC will fiddle them apart.
> The question, when a notifcation is send, is done in the PLC,
> and there should be some code, that compares the old and the new value.
> The parameters you are asking for are all defined by Beckhoff.
> Because of that, we are reluctant to repeat the documentation.
> What we can do, is to provide some best practise, may be.
> For a handful of variables I don't expect major problems.
> When we use a zillion of variables, things may need some fine tuning,
> either in software, or go for faster hardware.
>
> As you know, this is an open source project.
> Contributions, feedback or other questions are always welcome.
>
> HTH,
> please don't heasitate to ask more questions.
> /Torsten
>
>
>
> On 2026-02-18 16:04, Majer Karel wrote:
>> Hello Torsten,
>>
>> I think some concise overview of the possible options usable in INP
>> and OUT links would be nice.
>> I understand the basic use, but it's not clear to me how the various
>> options for setting poll rate, sample rate and delay work, how
>> sampling rate and delay settings for ads driver interact with these,
>> and if it's important to match PLC cycle time or not.
>>
>> Best regards,
>>
>> Karel
>> ------------------------------------------------------------------------
>> *From:* Torsten Bögershausen <tboegi at edom.se>
>> *Sent:* Monday, February 16, 2026 11:02 AM
>> *To:* Majer Karel <Karel.Majer at eli-beams.eu>; tech-talk at aps.anl.gov
>> <tech-talk at aps.anl.gov>
>> *Subject:* Re: Record TIME field taken from another record's VAL
>> 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!e2Ig-ypHK-
>>> _tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYnbAooRXo$ tc3_ads_intro/115883019.html&id= <https://urldefense.us/v3/__https://infosys.beckhoff.com/__;!!G_uCfscf7eWS!e2Ig-ypHK-_tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYn3PZmGS8$ 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!e2Ig-ypHK-
>>> _tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYnNIwp_Bc$  <https://urldefense.us/v3/__https://github.com/epics-__;!!G_uCfscf7eWS!e2Ig-ypHK-_tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYnPEsneLY$
>> modules/twincat-ads/> <https://urldefense.us/v3/__https://github.com/
>> epics-__;!!G_uCfscf7eWS!e2Ig-ypHK-
>> _tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYnPEsneLY$
>>> 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!e2Ig-ypHK-
>>>> _tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYnoPsVpG4$ <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
>>>> https://urldefense.us/v3/__http://www.eli-beams.eu__;!!G_uCfscf7eWS!
>>>> e2Ig-ypHK-
>>>> _tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYnw2XNBl4$  <https://urldefense.us/v3/__http://www.eli-beams.eu__;!!G_uCfscf7eWS!e2Ig-ypHK-_tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYnw2XNBl4$ > <https://urldefense.us/v3/__http://www.eli-beams.eu__;!!G_uCfscf7eWS!e2Ig-ypHK-_tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYnw2XNBl4$
>> <https://urldefense.us/v3/__http://www.eli-beams.eu__;!!G_uCfscf7eWS!
>> e2Ig-ypHK-
>> _tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYnw2XNBl4$ >> <https://urldefense.us/v3/
>>> __https://urldefense.us/v3/__http://www.eli-beams.eu/__;!!
>>> G_uCfscf7eWS!e2Ig-ypHK-
>>> _tCLuRgVos2YoEjuSyQSQj1J9wcVPAeL0WvE2Yz0TEkTzRNmcntIpdqUOpy4OIwxYn_QGsA0g$
>>>> __;!!G_uCfscf7eWS!euLXnna7-qCt-D3EjV5-bjzosTfKt-
>>>> sd4lVcov9BLro2tBUjLRx- ed8iuDCVso9vUKL04d9SoJjsUQ8dHHIoBcTijQcDzg$>
>>>>
>>>>
>>>
>>
>