State views are refreshed by V5SerialDevice every 200 milliseconds by default. 
await device.refresh();

console.log({
  brainAvailable: device.brain.isAvailable,
  battery: device.brain.battery.batteryPercent,
  systemVersion: device.brain.systemVersion.toUserString(),
  fieldConnected: device.isFieldControllerConnected,
  matchMode: device.matchMode,
});

for (const smartDevice of device.devices) {
  console.log(smartDevice.port, smartDevice.type, smartDevice.version);
}
Disable autoRefresh when the application controls polling itself. Call refresh() before reading views that must reflect the latest response.