| Technology | Time source | Needs | Best for |
|---|---|---|---|
| Independent RTC | Clock’s own crystal | Power only; set once | Simple, economical time display |
| GPS | Satellites via antenna | Antenna with sky view | Sites without (or not wanting) network dependence |
| WiFi | Internet time | WiFi network or hotspot | Offices, schools, retrofits |
| NTP / PoE | Your NTP server | Ethernet LAN (PoE optional) | IT-managed campuses, hospitals, control rooms |
| Master-slave | One master clock | RS485 / PLCC / wireless links | Railways, airports, very large sites |
Every option shows the same time across your site except independent RTC clocks, which are set individually. See our Solutions pages for architecture details.