TimeSync Not Working

[JeffS]

I just tried to use the TimeSync configuration in a Do-more setup I have.  One Do-more is the server the other is a client.  Update interval is 1 min.  I have sat and watched this but the time on the client Do-more never updates and the $TimeSynced never turns on.  Any thoughts to what I am missing?

Server:
IP - 10.52.19.0
Subnet - 255.255.252.0
Module - 1

Client:
IP 10.52.18.51
Subnet - 255.255.252.0
Module - 2

Thanks,
Jeff

[BobO]

TimeSync uses broadcasts. Are both units on the same broadcast domain? Routers generally don't pass broadcasts, although switches generally do.

[JeffS]

This is a stand alone network with one switch between the Do-mores.  No routers involved.

[BobO]

There's really not a huge amount that can go wrong. As long as both units are in the same logical network and broadcasts are being passed, the unit set as server (or alternate) will broadcast a time packet (three times, five seconds apart) at the specified interval, and any unit currently acting as a client will set his time and set the synced flag. I just tested with a BRX as server and a 205 as client and it's working as expected.

You did write the sysconfig change to both PLCs, right?

The next step I would go to would be to get a Wireshark trace and make sure the sync packets are being sent.

[JeffS]

Did a Wireshark trace and these are the only broadcasts I see from any of the Do-mores.

I tried wiping the PLCs and re-writing the program just to make sure there wasn't some strangeness happening.

[BobO]

Those are all ARPs, and our broadcasts definitely don't show up as ARP. My money is on the switch blocking unknown broadcasts.

[JeffS]

You are correct, swapped out switches and now it is working.

[BobO]

You are correct, swapped out switches and now it is working.

Awesome!