NTP Server For ION8650C Time Synchronization

[Mariana17]

Hello community!

I have an GPS, model GE Reason RT3000-R2, which has the feature of NTP server. I would like to sync the ION8650C time with it. So, I set up the power meter as follows:

In the Clock menu:

In Communication > Advanced Ethernet > NTP:

At first the meter did not receive any response from the GPS, the synchronization failed. Because there was no communication between meter and GPS.

After making a network change, the meter synchronized with a totally wrong time. At one point, I figured the time on the GPS was wrong.

But the value of “Time Sync Count” did not increase at any time. That is, the time has changed, but it is as if the meter has not received an update request from the server through this protocol.

At one point the meter was set to “Line Freq”, it may have been synchronized in some other way? Or even be syncing with the NTP server without incrementing this value? Currently, it is varying between two dates, would it be syncing internally with the crystal and then with the GPS, alternately, without changing the value of “Time Sync Count”? 

[Charles_Murison · Accepted solution]

Hello @Mariana17 ,

A few items to discuss on your post

1) "Value of “Time Sync Count” did not increase at any time. " When meter is set to NTP sadly this register does not update. The event log messages "Time about to change" and "Time Change" shows that meter is time sync'd with NTP server.

2) The different time ranges would suggest that something in the NTP message to the meter is not what the meter expects. The NTP time packet has 4 elements used by the meter, Reference Timestamp, Originate Timestamp, Receive Timestamp, Transmit Timestamp. The meter will do some math with these timestamps and use the results to calculate what change needs to happen. 

What I have seen happen in the past is inside the NTP packet from NTP source, the time for Transmit Timestamp is less than Receive Timestamp. Physical this cannot happen as the NTP source cannot send out a message before it has received the message asking for NTP response be sent. The math inside the meter will create a large negative number that the meter then applies to the current timestamp resulting in the shift to 2091.

Would need to confirm this is happening with a packet capture like Wireshark. Not always easy to capture the traffic, usually need a switch where port forwarding can mirror all network traffic to/from meter.

Regards,

Charles