Real-Time Clock
For the time display on a R7, see Real Time Clock.
The SLR Series Repeaters contain a Real-Time Clock (RTC) which is used by the repeater to keep track of the actual time[1]. This RTC can be used to timestamp data such as alarm and diagnostic logs. Any application showing these logs should be able to show the logs with timestamps that contain the year, month, day, hour, minute, and second. There is a rechargeable battery, which is used to keep the RTC operating when the repeater is turned off or disconnected from power. The RTC can remain operating with power supplied from the rechargeable battery for approximately 23 days. Once the battery is fully discharged, it will take approximately 33 hours to recharge once power is restored.
The RTC must be synchronized to a time source at least once every 24 hours to maintain the most accurate timestamps. The recommended time source is an Network Time Protocol (NTP) Server that all of the repeaters in the system can be configured to synchronize to periodically. If an NTP Server is not specified using CPS, then the CPS will sync the repeater’s RTC to the current time of the PC running the CPS. This should allow the RTC to be somewhat accurate, but it will become less accurate each day that it cannot be synchronized to an NTP Server.
In the event that the network where the repeaters are deployed do not have any local NTP Servers available, then a public NTP Server can be used instead. There are public NTP Servers available on the Internet that be used for this time synchronization. More information about NTP and the addresses for public NTP Servers can be found at: http://support.ntp.org and http://www.pool.ntp.org.
RTC Synchronization to NTP servers can be configured through CPS by specifying one of the following: the IP Address of the NTP Server, the DNS Address of the NTP Server, or that the NTP Server Address should be queried from the DHCP Server. The DHCP Server is usually present on network routers, but not all DHCP Servers support assigning the NTP Server Address to devices on the network.
It should be noted that the RTC based timestamps will only be available on SLR Series Repeaters. All other repeaters will continue to report diagnostic and alarms logs with timestamps that equate to the number seconds since the repeater last powered up.[2]
See Also
Real Time Clock (radio feature).