Communication and Audit Logs

Audit user access, diagnose power-line communication noise, investigate ARM system events, and verify protection settings with SUN2000 communication logs.

Beyond operational and hardware health data, the SUN2000 maintains a set of logs that record who accessed the inverter, how reliably it is communicating with the monitoring system, what the ARM operating system is doing internally, and what protection settings are currently active. These logs are your primary resource for resolving disputes, diagnosing intermittent monitoring dropouts, and verifying that a third-party service visit did not leave the inverter misconfigured.

usrmg_usrlog_2 — User Management Log

usrmg_usrlog_2 records every login event on the inverter, including the identity of the user, the time of access, and which interface was used.

Contents:

• Username or account identifier for each login event
• Timestamp of each access
• Interface used (Bluetooth / FusionSolar App)

O&M use cases:

• Resolving shutdown disputes — if an inverter stopped generating unexpectedly and both the site owner and a service engineer deny responsibility, usrmg_usrlog_2 provides an objective answer. A Shutdown command requires a deliberate user action through a specific interface; the log records exactly who issued it and when.
• Security audits — reviewing this log after any third-party service visit confirms whether settings were accessed and whether changes were made during the visit.

plc_featdata and cco_log — Power Line Communication

SUN2000 inverters can communicate with each other and with the SmartLogger over the AC power cables using Power Line Communication (PLC). plc_featdata stores noise and error statistics for the PLC channel, while cco_log records coordination events from the PLC Central Coordinator (CCO).

Contents:

• Noise level on the AC power line
• Error rate on the PLC channel

O&M use cases:

• Diagnosing monitoring dropouts — if inverters are frequently disappearing from the FusionSolar monitoring dashboard, the problem is usually either a network configuration issue or electromagnetic interference on the AC line from nearby industrial equipment (variable-frequency drives, welding equipment, large motors). plc_featdata and cco_log show whether the noise level on the AC line is elevated and whether the PLC error rate spikes at specific times, which helps you identify the interference source and schedule.
• Validating PLC infrastructure — on large sites with many inverters sharing a PLC network, these logs confirm whether all devices are communicating reliably or whether specific segments of the installation have degraded PLC signal quality.

run_log — ARM System Log

run_log is the ARM processor’s system journal. Unlike the operational logs generated by the DSP, run_log records what the inverter’s high-level software is doing: which modules load at startup, whether memory errors occur, and what the Bluetooth stack is reporting.

Contents:

• Module load events at startup and during runtime
• Memory error events
• Bluetooth communication log

O&M use cases:

• SmartLogger freezes — if a SmartLogger regularly stops responding or requires manual reboots, run_log from the connected inverters can reveal whether the ARM processor is experiencing memory errors or communication stack crashes that are propagating to the logger.
• Firmware update failures — if an OTA firmware update does not complete successfully, run_log records where the process failed. This gives Huawei support engineers a starting point for diagnosis without requiring a site visit.

cfg_file_ctrl — Control Configuration

cfg_file_ctrl stores the inverter’s active protection configuration: the voltage and frequency thresholds at which it will trip, and which protection functions are currently enabled.

Contents:

• Active voltage limits (upper and lower)
• Active frequency limits (upper and lower)
• List of enabled protection functions

O&M use cases:

• Post-visit configuration verification — after any third-party service visit, read cfg_file_ctrl and compare it against the settings from your last known-good export. Some service engineers reduce protection thresholds (for example, widening the acceptable voltage window) to prevent nuisance trips and increase apparent generation figures. While this may look good short-term, it exposes the inverter and connected equipment to conditions outside their design limits.

Always export cfg_file_ctrl before and after any third-party service visit. A reduction in protection thresholds — such as a wider overvoltage or overfrequency window — may not be immediately visible in monitoring dashboards but can cause long-term equipment damage or void the manufacturer warranty.