GPS Synchronization

I learned something new here, again.

Although the use of DCS to describe Distributed Asynchronous Clock Synchronization has been made the earlier and more traditional use of DCS is to describe a Ditributed Control System, and the OP used that term. I believe he has looked at the documents to make that definition. Rather than jump into a different use of the term DCS we should probably make use of the need for the time accuracy on the particular DCS application. I have seen many DCS (distributed control systems) that had need for high accuracy time and location. This may very well be the need. Other later comments talked about the use of beacons that might need to be sychronized but that pales in comparison to factory application where large multi-ton pieces move at several hundred miles an hour and must be precisely synchronized to avoid problems. I inspected a site that a huge piece of pipe (8 inches diameter by40ft) was ejected through the roof of a factory into a parking lot because a manager insisted a sensor be defeated in programing rather than replaced. The manager was replaced. The receiving machinery was not positioned properly by the DCS without the sensor input. DCS (distributed control systems) need precise time stamps and positions also.

DCS = Distributed Control System

A good example of the use of DCS is in the windmill industry. All the windmill structures on a "farm" must have red flashing beacons for pilot identification per the FAA. To distinguish from other types of structures (towers, smokestacks, etc.), the beacons on all the windmills are to cycle on and off at the same time. Because the windmills are quite far apart, the easiest and cheapest way to do that is with the GPS time signal.

Does each tower have its own GPS (not too expensive anymore), or are they all networked? Thinking about it, my guess is the latter since they have to be, or should be, controllable from a central point. Otherwise someone would have to go to each tower to feather the blades or change some other parameter.

In computer networks, time syncing is used to age authentication certificates, file modification times, all kinds of communication interfaces.

It's been a while since I was in that industry, but at that time both were employed. I think the time stamp was GPS controlled at each site, but they were also networked for fault reporting.

The obstruction lighting system was independent of any other control system of the tower.

Not only was GPS timing used for synchronization, but the flash rate, duration, and intensity was modified based on time of day/night.

This is still in effect.

All networked power distribution communications and process controls use this type of time synchronization.

It is critical for identifying the "first out" point of origin when a power distribution system fault occurs in any networked control system especially if the system is part of the nationwide power grid.

The same is true for all military operations.