Hi,

is the NTP Server reachable? Check it with a Ping...

Regards,

Towome

Hi,

yes Maint LED flashes and there are entries in diagnostic buffer. Check Firmware of your PLC and Update.

Regards,

Towome

While offline with the PLC, download the hardware configuration (presumably, again).  If it succeeds and downloads, the NTP server should start updating time.  If however the hardware says it is identical, please check if there is a firewall between the NTP server and the PLC, and a different device and verify NTP server updates are working.

In the diag buffer, shortly after a PLC power cycle, an entry will be made if the NTP server update fails.  If it succeeds, the PLC system time should match the UTC time of the NTP server.

and.short

Hello all,

I am trying to get a S7 1200 cpu to sync time with an NTP server inside the same network subnet. I have done this many times in the past with s7 1500. However the 1200 seems as if it does not even try to contact the NTP server.

From past experience, if the time request fails, there are messages in the alarm buffer as well as the general Maintenance required status. I do not get any errors, nor does the time update.

Thanks in advance,

Andrew

What device are you using as NTP server?  Is it a windows PC?  If so, you need to enable firewall rules that allow NTP on the PLC network and block it on the business network - assuming they are distinct and both accessible from that windows PC.

I think most default firewall settings as well as active directory / windows domain settings prohibit NTP services being provided by regular workstations.

That exactly what I typically do with 2 network adapters.

Created 2 firewall rules.  Allow NTP opens up NTP port / UDP protocol for private (and public) networks (which our controls networks are).  Deny NTP on Domain networks.

That keeps the active directory happy because it has no idea about the NTP server.

Do you have an HMI in the same network configured to use the same NTP server IP?  Does it work?

I suspect if you look in the F1-Help for NTP, you may find you need to enable "no security" for NTP to work with V19.  Not sure as I have not ventured there (yet).

and.short

Thank you for your time in responding to my issue. I have downloaded hardware on many occasions. If you look at the screenshot (please disregard analog input messages), since the last hardware configuration load, the time has not updated, and there are no relevant NTP messages.

Could it be a known bug with the specific firmware(V 4.5.1)? I have same behavior from two identical CPUs.

Thanks again,

Andrew