Hi,

Unfortunately, this does not seem to be mentioned in any public documentation. So you would have to ask Siemens for a correct answer.

I also wonder why you need this information. I am pretty sure that the PLC does not have an NTP client, only NTPv4 support is implemented. And since an NTPv4 server is backward compatible, connecting to an older version should not be a problem.

Kind regards
Stefan

Hi,

As mentioned above, you would need to contact Siemens for clarification.

However, since NTPv3 is from the last century and NTPv4 was released in 2010, it is quite possible that the S7-1500 PLCs introduced in 2012 have built-in support for NTPv4. If not, they support NTPv3, which is supported by an NTPv4 server. This backward compatibility is explicitly defined in RFC 5905 (NTPv4 specification), which states that NTPv4 maintains interoperability with NTPv3 clients and servers.

Kind regards
Stefan