Read-only current reading from sensor 4: for a digital input this is simply 1 (active) or 0 (inactive); for an analog 4-20 mA input it is the sensor value after the falconInput4Gain/falconInput4Offset correction has been applied -- the value an admin actually watches (e.g. via polling or the falconInput4HighLimit/LowLimit alarms) to track that sensor's real-world reading such as temperature or humidity.