Get the current Gridshare operation mode of a device. Valid operation modes are:

• Simple: Follows the simplest plan possible for the device kind
• Schedule: Follows the periodical plan defined for the device
• Smart: The AI optimized smart plan for the device
• Unknown: The operation mode can not be determined

The tag field gives finer-grained detail as a device-specific mode name.

For Lunar devices, tag is one of:

• LunarBackup charges and holds the battery in reserve for grid outages - it is not dispatching for savings
• LunarSelfCons (self-consumption) balances charge/discharge to use the site's own solar
• LunarSmart follows Smart mode's AI-optimized daily plan, dispatched against the customer's tariff
• LunarTOU follows a fixed time-of-use schedule rather than an AI-dispatched plan
• LunarStandby is the installer app's 'Custom' mode - only settable there, not through this API
• LunarEmergencyBackup charges to full ahead of an anticipated grid outage
• LunarPrePTOBackup, LunarPrePTOSelfConsumption and LunarPrePTOStandby are the pre-PTO equivalents of Backup, Self-consumption and Standby above
• LunarPrePTODeepIdle is the pre-PTO idle state - neither charging nor discharging while awaiting PTO
• unknown means the device's home controller is set to an 'Other' mode that Gridshare doesn't recognise

A site needs 'Permission to Operate' (PTO) from the utility before it can export to the grid; until then a Lunar device's tag is one of the LunarPrePTO* values above instead of its post-PTO counterpart.