Which NTP/SNTP versions are supported by the BMENOC0311?
Which NTP and SNTP protocol versions can the BMENOC0311 use when exchanging time-synchronization traffic with an NTP server?
This FAQ is dedicated to the Modicon M580 BMENOC0311 Ethernet communication module, configured as an SNTP client and connected to an NTP time server, including a Windows NTP server.
The BMENOC0311 sends time-synchronization requests exclusively in SNTP format.
However, the module can receive and process responses from an NTP server using NTP versions V1, V2, or V3. These protocol versions are backward-compatible with the SNTP format and NTP V1.
The BMENOC0311 is not compatible with NTP V4. The module can neither send nor interpret NTP V4 frames.
Therefore, when a Windows NTP server responds using NTP V3, the BMENOC0311 can accept and process the received time-synchronization traffic correctly.