Computer time updating software
Latency is always the killer when trying to sync two or more devices together.
That is, essentially, the time it takes for the signal to travel from sender to receiver.
Or more specifically, an atomic clock in the Greenwich Observatory, is considered to be "Zero" time, or as the military refers to it "Zulu".
If you need to sync to UTC, you need a signal that is traceable directly back to that atomic clock and without too many hops (latency) between.
I will be in a place where there is no internet access. The only way I can synchronize time on two laptops is by using the GPS signal right?
-jack [Warning for the casual reader, this is way long and a little bit technical.] Jack, Apologies in advance if some of this is redundant for you but I need to do the whole thing in order to make sure I do it right.
Therefore, the microsecond accuracy that is available from Time Tools GPS T1000 and T2000 GPS timing receivers is not available with this software.
Hi Jack, Simple answer: they are correct that consumer navigation GPS devices do not output the PPS signal so a program like GPS Clock cannot give you any better accuracy than can be extracted from the data output from the GPS receiver. But there are so many factors they cannot control for that the best promise they can make is 1 second accuracy. Millisecond and microsecond accuracy are possible on a PC.
Standard NMEA GPS devices do not have a pulse per second output that can be utilised by the serial port of a PC.
These are highly stable clocks that were originally calibrated with UTC, so the signals that originate from them can be considered a good sync link back to UTC, and therefore a good source of synchronization on their own.
However, there are a few minor hitches in this that need to be understood.
But the crystal in the internal clock on a PC is about as accurate and stable as a cheap wristwatch (e.g. So in order to maintain stable timing at that level of accuracy in a PC you would need connection to an accurate time server like the T2000 that you can use to monitor the PC timing fairly frequently.
Or close proximity (~zero latency) connection to an NTP server that is connected to a T2000. What kind of application are you using that you want millisecond or microsecond accuracy? Hi ken, I do understand the difference between accuracy and stability but I am not sure about the PPS signal.
Naturally the next question is, If the pulses are coming only one per second, how can you get subsecond accuracy? Also, you don't need to worry about the stability (drift) of the computer's internal clock because you are getting a fresh pulse every second.