The heartbeat / serial communications LED blinks to indicate
the meter’s operation and serial Modbus communications status.
The LED blinks at a slow, steady rate to indicate the meter is
operational. The LED flashes at a variable, faster rate when the meter
is communicating over a Modbus serial communications port.
You cannot configure this LED for other purposes.
NOTE: A heartbeat
LED that remains lit and does not blink (or flash) can indicate a
problem. In this case, power down the meter and reapply power. If
the LED still does not blink or flash, contact Technical Support.