Hello @Mohammad Royvaran
No it is not possible to sync 2 WebDAQ 504s.
I don't know to what server your computer is sync'd.
Webdaqs use NTP to synchronize their clocks and calculate clock drift. They connect to pool.ntp.org, which are public NTP servers. We cannot spec the timing accuracy or synchronization of multiple units because it depends on the latency of the internet connection, number of hops to the NTP server, etc. This can vary for each of the units on the same network because things constantly change on the internet.
Regards,
Jeffrey
