DSNET Synchronization between R8's

Ronald Swecker

Posted on 27.10.2022 14:10

What is the correct means of synchronizing multiple R8's with DSNET? I have 3 - R8 systems that I want to have 1 R8 as the master and the other 2 as MU's. Whenever I attempt to daisychain the sync cables between the units (as I would with SIRIUS Slices) I get sync errors when attempting to collect data. I have been able to use NTP across all 3 systems, but this leaves an approximate 3ms difference between the different R8's.

Corey Schwanz
Support Tech Manager
Posted on 27.10.2022 16:58

@Ronald Swecker

The best way to accomplish this is by connecting the R8s together as you have already done but manually changing the time source on all three units. The reason this is required as opposed to connecting only SIRIUS units together like you are used to is that since each of the R8s has a dedicated computer they create their own time, so each R8 was considering itself to be the time source. We need to tell which of the three is the time source and the other two to look toward that unit as the leader.

On the Master unit you want to set the time source as your typical DEWESoft DAQ Devices and if Automatic make sure that it says IRIG-B DC or to manually change it to IRIG.

This means that your master unit is creating the IRIG signal, it is using that signal to sync all the internal R8 slices, and sending that IRIG signal out via the Sync ports.

On the two measurement units you need to change the time source to External and then manually select IRIG-B DC from the list of available options, like so:

This means that the measurement unit it will still operate on its own and be controlled via the OPT-NET instance but the timing source is coming from outside the unit. If you click on the little icon next to IRIG-B DC you can see exactly how this is set up.

My DEWE-43 is now looking for an IRIG signal coming from any external source, either a standalone clock or a different DEWESoft unit.

This should alleviate the timing and syncing issues you are seeing between your R8s. Please let us know how this goes.

Ronald Swecker

Posted on 28.10.2022 12:37

Thanks, worked perfect.

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