Summary #
GHL controllers can read a wide range of sensor types, use them for automatic regulation, trigger alarms, and record their history. This article covers all sensor-related settings — regulation, alarms, sensor-specific parameters, virtual sensors, and measurement data recording.
For more detailed explanations of individual settings, see the device-specific Programming Guides in the Downloads section below.
Applies to #
- ProfiLux 4 Series (incl. Industrial Line / IL)
- ProfiLux 3 Series
- ProfiLux Mini Series
- Software:
- GHL Connect (App, Webinterface, myGHL)
- GHL Control Center
Before you start #
- Sensor types supported: Temperature, pH, Redox, Conductance (Freshwater, Seawater, Brackish), Humidity, Air temperature, Oxygen, Voltage. Level sensors and Flow sensors are configured separately — see Level Control & Leakage Detection – Setup Guide and Flow Sensors – Setup Guide.
- Connection: BNC sensors connect either to a built-in port on the ProfiLux, to a ProfiLux Expansion Card, or to an Expansion Box. The analog temperature sensor uses a PS/2-style connector (ProfiLux 3 or Expansion Card), the Voltage sensor requires a PLM-ADIN Expansion Card, and the Oxygen sensor requires a dedicated Expansion Card.
- Calibration: pH, Redox, Conductance, and Oxygen sensors must be calibrated before first use and regularly thereafter — see Sensors – Maintenance & Calibration.
Configuration #
Open a sensor’s settings via Probe/sensor controls (GHL Control Center) or Control -> Sensors (GHL Connect App) and select it from the list. A Sensor overview page (GHL Control Center) or the sensor list itself (App) shows all current values at a glance. Some settings below are only visible in Expert view.
Basic Settings #
- Sensor Active: Enables monitoring and control for this sensor. Deactivate unused inputs to prevent false alarms.
- Signal Filter: Smooths short-term fluctuations in the measured value.
- Display: Selects the measurement unit shown, if the sensor supports more than one.
- Operating Hours: Tracks how long the sensor has been active; can be reset manually.
- Change Measurement Range (pH, Redox, or Conductance F/S sensor; internal sensors only; not on ProfiLux Mini): Switches the port between measurement ranges (e.g. pH ↔ Redox). For sensors on an Expansion Card or Expansion Box, the range is switched via the PAB or Expansion Card configuration instead.
Regulation (Probe/Sensor Controls) #
- Nominal Value: The target value the controller regulates toward.
- Hysteresis: Defines the switching points around the nominal value to prevent rapid on/off cycling.
- Cooling Difference (Temperature sensor only): Additional offset for cooling-related switching.
- 1-10V is max. at deviation of (Temperature and Air temperature sensor only): Sets the deviation from the point where cooling switches on — not from the nominal value itself — at which an assigned 1-10V interface reaches maximum output.
- Operation Mode Controller: Two-position controller (default), Pulse/Pause fixed, Pulse variable, Pause variable, or Off. Two-position covers most cases; the pulse-based modes fine-tune switching behavior for special setups and require a Pulse and Pause duration.
- Off During Feed Pause: When enabled, the sensor behaves as if inactive during a feed pause — the current value is still displayed, but regulation and alarm monitoring are suspended until the feed pause ends.
- To view the calculated switching points for this regulation, use the dedicated button in the App, or check the table at the bottom of the sensor page in GHL Control Center.
Nocturnal Change #
(Temperature, Air temperature, pH, Voltage, and Humidity sensors only)
- Active: Enables a scheduled adjustment of the nominal value between a start and end time.
- Change of: The amount by which the nominal value shifts during the scheduled window.
- Start Time / End Time: Defines the window during which the change applies.
Sensor-Specific Extras #
- Summer Switching (Temperature sensor only): Active toggle plus an Intensity setting for seasonal switching behavior.
- Temperature Compensation (Conductance and Oxygen sensors only): Choose a reference Temperature sensor, or enter a Man. temperature manually if no sensor is selected.
- Salinity (Oxygen sensor only): Choose a reference Conductivity sensor, or enter Man. salinity manually.
- Density Offset (Conductance Seawater sensor only): Corrects the displayed density value if it deviates from an independent reference measurement (e.g., a refractometer).
Alarm Settings #
- Alarm: Enables alarm monitoring for this sensor. In the App, this is an Active toggle plus a separate No alarm on water change option (not available on ProfiLux Mini). GHL Control Center combines both into one dropdown: Not active, Active, or Active, except while AWC.
- Deactivate Control: Turns off regulation for this sensor while an alarm is active.
- Max. Deviation: The deviation from the nominal value that triggers the alarm.
- To view the calculated alarm thresholds, use the dedicated button in the App, or check the table at the bottom of the sensor page in GHL Control Center.
Measurement Data Recording #
- App: Toggle Save Values on the sensor page to record its readings, and set the Sample Period (applies to all sensors).
- GHL Control Center: Under Probe/sensor controls -> Measurement data, check which sensors should be recorded and set the Measurement period. This page also shows local storage usage and lets you view a chart, export recorded values, or clear the stored data.
Virtual Sensors #
- A virtual sensor is either a copy of a physical sensor or an average of two physical sensors of the same type, useful for example to run a separate regulation on the same measurement (e.g. two heaters reacting to different nominal values from the same temperature probe).
- Virtual sensors are currently created and removed only via the ProfiLux display: System -> Virtual probes -> New Virt. probe, then select the type (Copy or Average) and the source sensor(s), and confirm with Yes. To remove one, repeat the first two steps and select the virtual sensor to delete.
- Once created, a virtual sensor is configured on its own sensor settings page exactly like a physical sensor (regulation, alarm, etc.), except it has no Calibration data section.
Notes #
- For calibration and routine sensor maintenance, see Sensors – Maintenance & Calibration.
- For automatically shifting a sensor’s nominal value based on another sensor or a file, see Dynamic Nominal Value – Configuration Guide.