Experimental Physics and
Industrial Control System

Hi

 

This issue happened with base 3.14.12.3 and 3.15.6. What happened is that the IT group upgraded their MS windows active directory servers, one of the included services in the update is the NTP. When all the servers rebooted, the NTP service did not start and caused a 3-hour time shift forward in time on all connected PCs and hosts.

 

On the IOC side, when the shift happened the IOC date command returns the host's date/time. But when the problem was resolved by the IT group, the time got synchronized and went 3-hour backward in time. At this moment the date command returns the same timestamp, i.e., a frozen time stamp. We had to reboot every IOC to get the machine working.

 

My question is, is there any explanation for this behavior and any potential way to avoid it? Also on daylight saving times, we can't recall this issue happening on a DST switch before most probably because the machine was OFF, will DST switch give the same effect? The issue is reproducible with any IOC, whenever the IOC's timestamp is ahead of the host's time stamp, the IOC's timestamp will get frozen,

 

Best Regards,

 

Abdalla Ahmad

Control Engineer

SESAME

Allan, Jordan.

Tel: (+962-5) 3511348 , ext. 265

Fax: (+962-5) 3511423

Mob: (+962-7)88183296

www.sesame.org.jo