Symptom
Time synchronization failure
- ID
symptom:time-sync-failure- IRI
https://solarlattice.org/kb/symptom/time-sync-failure- Status
- active
- Also known as
- Time synchronization failed
On SMA STP-US inverters, this symptom shows up in the event log as event 10110, which means the inverter could not get time information from its configured NTP server. Check the NTP server settings in the inverter first. Next, make sure the inverter is connected to a local network that has Internet access. In the same event log, events 10108 and 10109 record the old and new time when the clock is adjusted, which helps show when synchronization last worked. On SEL-735 revenue meters, check the IRIGOK and TSOK bits: these are set only while meter time comes from an IRIG-B source, and TSOK also requires enough accuracy for synchrophasor measurement. Where SNTP is used, accuracy depends on the server and the network, and it is best with few switches and routers between the server and the meter.
<!-- review notes
- sentence 2: support check: partial - Checking NTP server configuration is a listed corrective measure, but the passages don't say to do it first (it is listed first).
- sentence 3: support check: partial - Network with Internet connection is a listed corrective measure, but the passages don't state an order (next/second), though it is listed second.
- sentence 4: support check: partial - Events 10108/10109 are listed as time adjusted old/new time, but the passages don't say they help show when synchronization last worked.
-->
Claims
observed_as
c1 verified · fact
NTP time query failure
SMA inverters log event 10110 when they cannot get time information from the configured NTP server. Suggested checks: confirm the NTP server configuration and confirm the inverter is on a local network with Internet access.
No time information could be called up from the set NTP server.
verified by: review-workflowverified on: 2026-10-20review note: support check: partial - SMA event 10110 and both checks are stated, but the SEL-735 TSOK/IRIGOK note is not in the cited passages for the NTP measurement, and the statement mixes the two.
c2 verified · fact
Time sync OK flag cleared
On SEL-735 meters, the TSOK bit is set only while meter time comes from an IRIG-B source accurate enough for synchrophasor measurement. IRIGOK is set while meter time comes from IRIG-B at all. If these bits are cleared, the meter is not synchronized to that source.
verified by: review-workflowverified on: 2026-10-20review note: support check: partial - TSOK and IRIGOK assert definitions are given, but the passages don't state that cleared bits mean the meter is unsynchronized or that time-sync failure is observed that way.
Referenced by
Data