Improvements and fixes

The plant's outages, device faults and event times now read as the devices actually ran.

• A combiner box that reports zero power against its own live readings no longer opens an outage.
• A silent inverter is added to the plant alarm after 12 hours.
• Two data loggers can now be added, reading combiner boxes, strings, the grid meter, irradiation and temperature sensors, and curtailment limits.
• A plant-wide grid trip is no longer filed as a device fault.
• Event times from the data logger are no longer off by the timezone offset.