Sapling’s Master Clocks – GPS as a Time Source


Employees that work in an organization that has a synchronized clock system installed typically only see the secondary analog or digital clocks. But there is another clock behind the scenes that many people don’t see or even think of and that’s the master clock. The main objective of the master clock is to provide the most accurate time to the secondary clocks within a system. Typically, there are two ways that the master clock can receive time and those are through an NTP (Network Time Protocol) server or a GPS receiver. Receiving time from an NTP server comes as a standard option with all of Sapling’s master clocks. As for receiving time through GPS, this option must be requested by the customer. For this post, I would like to focus on GPS and provide more information about this specific time source.

If a user decides to receive the time from a GPS satellite, there is a receiver that comes with the master clock which sends out the clock system’s location to satellites orbiting the earth. The satellite recognizes the location of the receiver and delivers the exact time in that particular location. Following that, the GPS receiver relays the accurate time to the master clock, which distributes it out to all of the secondary clocks.

Besides the receiver that goes along with the master clock, two additional items are required in order to utilize GPS as an option: A dome antenna and a GPS cable. A dome antenna must be mounted to an area (typically a roof) that has a clear view of the sky in order to receive the best signal. As for the GPS cable, this item connects the dome antenna to the master clock. Sapling offers the cable in three different sizes to accommodate any size facility: 75 ft. (22.8 cm), 150 ft. (45.7 cm) and 300 ft. (91.4 cm).

As I mentioned earlier, receiving time from an NTP server comes standard with all of Sapling’s master clocks. If you decide to utilize the GPS option, the master clock will also allow you to utilize an NTP server as well. You can also choose which time source (GPS or NTP) will be the main time source for the master clock and which one will be a backup source. By choosing both features, you can enjoy having redundancy from both time sources.