The time zone, date, and time used by all devices connected to a Metasys site are synchronized automatically, preventing errors from manual time entry and clocks that become inaccurate over time. Network-wide time management ensures that scheduling, trending, audit trailing, data collecting, time-stamping of alarms, and other functions that require accurate time management use the same time zone, date, and time consistently for all system operations.
Time synchronization occurs on the Metasys network when an engine or server sends an IAmLive message to the Site Director. If the IAmLive message fails, the engine or server sends another message to retrieve the time from the Site Director. When the time is synchronized between the devices, a second IAmLive message is successful.
For network-wide time synchronization, the network engine or ADS/ADX designated as Site Director is the device time server because it provides the time zone, date, and time for all other engines/servers on the site. All other devices are considered time clients because they receive the time zone, date, and time from the Site Director. Beginning at Release 8.0, multiple time zone support was made available for upgraded network engines. The network engine or ADS/ADX designated as Site Director remains the device time server, but for network engines at Release 8.0 or later, the time synchronization occurs in UTC time, not in the time zone of the Site Director. For more details, see Multiple time zones.
To set the date and time in the Site Director (and therefore the entire site), you can set the time manually or select a time server for the Site Director. The time server for the Site Director is referred to as the site time server and should be a reliable source that is not on the Metasys network. Regardless of how you set the date and time, you must set the time zone in the Site Director.