NTP Client Configuration |
NTP, or Network Time Protocol, is a protocol designed to synchronize the clocks of computers over a network. The use of an external NTP time server allows the NetRS to set its own internal clock when GPS is not available, such as when the receiver powers up. This can be helpful if the receiver has been off for more than a few days and in some situations it can help to reduce the amount of time required to acquire satellites and begin logging or streaming data. Once the receiver begins tracking GPS satellites, the GPS time solution will be used as the time source. The GPS time solution is always the primary time source when it is available.
The NTP Client is configured using the NTP Client Configuration page, accessible through the Network - NTP Client menu item. To use external NTP time servers, specify the addresses of up to three servers in the External Time Servers fields. Each address can be specified as an IP address, such as 206.40.88.30, or by using a network name, such as gpstime.trimble.com. Note that if the network name is used, then an external DNS server must be available to the NetRS, and that server must be configured in the Ethernet Configuration pages.
Use the OK button to accept any configuration changes.
NTP Client operation can be disabled by clicking the checkbox labeled "Disable using NTP time servers". This will erase all time servers fields and no attempt will be made to use an NTP server to synchronize the internal clock. Accurate time will not be established until the receiver starts tracking GPS satellites.
The NetRS is always enabled to act as an NTP Server (as opposed to an NTP Client). Other network devices can always query the NetRS using NTP protocols to determine accurate time based on GPS signals. This feature is independent of the configuration of the NTP Client and cannot be disabled.
Detailed information about NTP and a list of public NTP servers can be found at the NTP project website.