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cRIO PTP time sync: 35 second offset?

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Hello,

 

I'm new to the PTP protocol, and I'm trying to sync the date/time among 2 CompactRIOs and a GPS clock (a Tekron TTM 01-E).

 

The PTP network comms are working fine: I can set any of the 3 devices as Master, and the other 2 will follow its time. Notably, when I force the Tekron clock to be a Slave, it will ignore the GPS value and track the cRIO value.

 

However, regardless of which device is Master, the cRIOs' times will always be ~35s ahead of the Tekron time. The 2 cRIOs will always have the same time.

 

Why might this be? How can I get rid of this offset?

 

I'm not sure if this is an issue related to cRIO config or generic PTP config. I've attached a screenshot of the 2 control panels if it provides any clues. Any guidance/insight will be much appreciated!

 

PTP.png

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Accepted by topic author JKSH

35 seconds is the current offset between the UTC and TAI timescales. PTP typically uses the TAI timescale, but not always. Is your Tekron device configured to report UTC time when it is the master?

------
James Blair
NI R&D
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Thanks James, I wasn't aware of the offset between TAI and UTC. You're right, the Tekron software was reporting UTC time.

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Hi JKSH,

 

we'are tring to synchonize a sbRIO 9606 and a cRIO9076 using PTP time sync without success. 

 

From MAX I have installed the following add-ons on the two real-time targets:

- NI 1588-2008 Network Management 14.0.0 

- NI-TimeSync 14.0.0

-NI-TimeSync Plug-In for software based 1588 14.0.0

 

From the tab "Time Settings" the "Software 1588 time protocol (Ptp)" is enabled, but I can't get any kind of syncronization.  

 

Can you explain to me the procedure you followed to synch your hardwares?

 

Thankyou very much!

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Hi TizianoTuccella,

 

I've replied to your other thread at http://forums.ni.com/t5/LabVIEW/cRIO-andsbRIO-PTP-TimeSync/m-p/3033221 . Please don't double-post, especially since your issue is not related to this thread.

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