In various embodiments, the heartbeat can be provided multiple times within the threshold time period to help ensure that the circuitry can receive the heartbeat within the threshold time period even if one of the heartbeats is not properly received by the circuitry. As one particular example, in one embodiment, the heartbeat indication can be provided 2-3 times within a 10 second period.

As another example of how the heartbeat indication can be provided, in one embodiment, the magnitude of MPPT steps for MPPT tracking can be modified. For instance, in one embodiment, during normal operation the inverter can adjust the amount of power it is drawing by changing the string current (and voltage) up or down in small steps every few seconds. In one embodiment, a more complicated and recognizable pattern of MPPT step changing can be used (e.g., go up for 1 second, down for 2 seconds, etc.) such that circuitry can detect that the MPPT pattern is indicative of normal operation of the inverter and therefore the circuitry can determine to keep the PV module enabled.

Other examples of providing and receiving the heartbeat indication also exist as described throughout the specification.

The disclosed structures and techniques can provide for safety shutdown and/or startup in a safe and orderly manner to help facilitate installation, maintenance, and emergency work at or nearby an array while inhibiting downtime and unnecessary shutting down of the array.

Turning now to FIG. 4, example circuitry 400 configured to implement one or more portions of the disclosed techniques is shown. Circuitry 400 can be any suitable device, including, but not limited to module-level electronics, etc.