Time synchronization

The rc_reason_stack provides timestamps with all images and messages. To compare these with the time on the application host, the time needs to be properly synchronized.

The current system time as well as time synchronization status can be queried via REST-API and seen on the Web GUI’s System page.

Note

Depending on the reachability of NTP servers or PTP masters it might take up to several minutes until the time is synchronized.

NTP

The Network Time Protocol (NTP) is a TCP/IP protocol for synchronizing time over a network. A client periodically requests the current time from a server, and uses it to set and correct its own clock.

By default the rc_reason_stack tries to reach NTP servers from the NTP Pool Project, which will work if the rc_reason_stack has access to the internet.

If the rc_reason_stack is configured for DHCP (which is the default setting), it will also request NTP servers from the DHCP server and try to use those.

Additionally, the user can specify up to three NTP servers manually using the REST-API’s /system/ntp endpoint. A more convenient way is setting the NTP servers on the Web GUI’s System Time page.

PTP

The Precision Time Protocol (PTP, also known as IEEE1588) is a protocol which offers more precise and robust clock synchronization than with NTP.

Setting time manually

The rc_reason_stack allows to set the current date and time manually using the REST-API’s /system/time endpoint, if no time synchronization is active (see System and logs). A more convenient way is setting the system time on the Web GUI’s System Time page.