The DAL Operating System offers two options to configure a time source.
The time configuration under WebUI>Configuration>System>Time>Time sources are passed settings to the "ntpdate" program at startup, and when there is a networking change, it updates the system time. "ntpdate" only adjusts the time once.
The system time in the DAL Operating System is synchronized at startup by "ntpdate" command to a remote NTP server or to the time reported by the modem (cellular as a time source) or GNSS module and in response to a change in the default route, but at no other time. If the system stays up for an extended period, clock drift could start to occur.
The time configuration under WebUI>Configuration>System>Time>Time sources are passed settings to NTP daemon.
The DAL Operating System can also act as an NTP server, serving up time to NTP clients on the network that request it.
If the NTP server is enabled, the ntpd daemon is started. It queries the time servers that are configured under Service>NTP (which are in fact aliases to those under System>time>NTP). While ntpd is running it periodically updates the system and hardware clocks itself; "ntpdate" won’t run if “ntpd” is already running.
NTP daemon can obtain time via NTP server, using GNSS module of the modem or fall back to local system clock
The GNSS source takes precedence over NTP servers.
If the parameter to allow the on-board GNSS module to be used as a time source is enabled, the NTP server may take longer to sync. In addition, if the GNSS module was not previously in use (not specified as a source in Service>Location), enabling this parameter will power on the GNSS module and start gpsd - which will impact power consumption and CPU cycles.
Last updated:
Feb 21, 2024