The Simple Network Time Protocol

The Simple NTP, as the title says, implements a simplified version, but compatible NTP as it use the same package, but the filter aplied is much leaner and therefore less accurate. Therefore, according to the RFC, it recoomends to use SNTP only in the last layer of synchronization, that is the layer of PCs.Starting with version 4.2.2 of G.A.B. all systems supprted by GF_Project Vx are carried with sntp client, that can be anabled by appropriate options in a separate configuration page inside the setup program.The necessari parameters are the IP address and port number of the NTP or SNTP server which you want to connect. The default port is n. 123.In the configuration page, you can alse test the connection and get an istant feedback on the configuration of the system.When you enable this feature and the server ntp is reacheable, all the settings of data/time from the HMI are inhibited because is the server that have the priority.If the system is connected to the ethernet and have a ntp server configured and reacheable, the data time is achieved at the startup before starting of user program.To avoid losses of seconds in timestamping, if the time read after startup of plc was quite different, the system will apply a graceful adjustment.If the system isn’t able to sychronize data time at the startup (es. Cable disconnected or server ntp down), but only after some time, it may be a lot of time before to see the two data time perfectly sinchronized. So take care on cable correctly inserted and on ntp configuration. Note that until the system is not connected you can change manually the data time.