array(8) {
  ["version"]=>
  int(2)
  ["device_id"]=>
  int(6558)
  ["pulse_count_value"]=>
  int(0)
  ["pulse_interval_value"]=>
  int(600)
  ["pulse_interval_unit"]=>
  string(1) "s"
  ["cumulative_pulse_count_value"]=>
  int(0)
  ["battery_voltage_value"]=>
  float(3.227)
  ["battery_voltage_unit"]=>
  string(1) "V"
}