Synchronization over Ethernet

[DaveBarnett]

I have an application in which I'd like to synchronize 2 or more PowerPmacs which are in disparate locations (so, sharing physical clock signals is awkward). By synchronize, I mean be able to start motion programs on the same RTI cycle and maintain zero drift over time. I understand some of you folks in the astronomical field may be doing something similar using UTC. ??

 

Can pmac's powerful external time base features be combined with something like NTP or PTP (Precision Time Protocol) over ethernet on the Linux side ??

 

see:

 

https://sourceforge.net/projects/ptpd/?source=directory

 

Thanks !

[bradp]

Why not consider using Ethercat and a Master to Master bridge by the EDC company. The Master to Master bridge by EDC allows you to have a DC clock which will keep the Pmac's synchronized. It is also a shared memory between the Pmacs so you can pass data from one to another with I believe a 1 or 2 Ethercat cycle delay.

[DaveBarnett]

Thanks, Brad. I'm afraid I'm not familiar with this company. Can you provide a link to their website..or ?

[bradp]

Yep, sorry, it is the company ESD

 

ESD Master to Master bridge

ECX-EC Manual (Doc. No.: E.3022.21 / Rev. 1.1)

https://esd.eu/en/products/ecx-ec

 

 

Attached are my setup notes if you are using the Etherlabs Naster

PPMAC ECX-EC setup guidline 01.zip

[DaveBarnett]

Thanks, Brad. That is an interesting approach. What was the application that you were handling with this method? Of course, a software only approach is attractive from a cost standpoint, and I'd like to be able to avoid EtherCAT unless other constraints demand it. So, no DT users syncing over the ethernet port ??

[bradp]

We had a pPmac as part of a larger system and the host PC must synchronize all systems to its demands.

 

If you do not like Ethercat then I am sure you can do this with some RT Ethernet system, you must just engineer it all.