End-user manual for the greenhouse climate control system. This manual describes every settings screen and explains what each parameter does in plain language.
The measurement screens give a live overview of what the greenhouse is doing right now. All values are read-only — nothing can be changed here. Screens only appear when the relevant hardware is connected.
This is the main overview screen for the greenhouse climate. It shows the current sensor readings alongside the setpoint the controller is aiming for (the calculated setpoint).
| Value | Unit | Type | What it shows |
|---|---|---|---|
| Temp measurement | °C | Live | Current inside air temperature measured by the sensor. |
| Temp calculated setpoint | °C | Calculated | The temperature the controller is currently working towards, taking into account the active period and any slope transitions. |
| Humidity | % | Live | Current relative humidity inside the greenhouse. |
| Humidity c-setpoint | % | Calculated | The humidity target for the current period. |
| Heating status | — | Status | Current state of the heating system: Off, Standby, or Running. |
| Heating signal | % | Live | How hard the heater is currently working (0 = off, 100 = full output). |
| Heating c-setpoint | % | Calculated | The target output level the heating controller is aiming for. |
| Fogging status | — | Status | Current state of the fog system: Off, Standby, or Fogging. |
| Fog signal | % | Live | Current fog output level. |
Shows the live status of all ventilation windows. The controller drives each window to its calculated setpoint; the actual opening follows as the motor moves.
| Value | Unit | Type | What it shows |
|---|---|---|---|
| Temp calculated ventilation | °C | Calculated | The temperature at which ventilation is calculated to start opening. This is the temperature setpoint plus the ventilation addition offset. |
| Wind side | — | Status | Whether this window is currently behaving as the leeward (sheltered) or windward (exposed) side. The controller may switch sides based on wind direction. |
| Ventilation status | — | Status | Current window state: Closed, Opening, Open, Closing, or Blocked (e.g. by rain or storm). |
| Ventilation 1 / 2 | % | Live | Actual current opening of the window (0 = fully closed, 100 = fully open). |
| Ventilation c-setpoint | % | Calculated | The target opening the controller is working towards, after applying all wind and rain limits. |
| Ventilation total c-setpoint | % | Calculated | Combined ventilation setpoint for both windows together (sum, max 200 %). |
Shows the live status of the hot-water pipe heating circuit. The heating pipe carries hot water from the boiler through the greenhouse; a mixing valve controls how much hot water enters the circuit to reach the pipe setpoint.
| Value | Unit | Type | What it shows |
|---|---|---|---|
| Heating c-setpoint | °C | Calculated | The current air temperature target, used as the basis for all pipe temperature calculations. |
| Pipe min. setpoint | °C | Calculated | The minimum pipe temperature calculated for this period, combining the period setting and any humidity influence. |
| Pipe measurement | °C | Live | Actual water temperature measured in the heating pipe. |
| Pipe c-setpoint | °C | Calculated | The pipe temperature the controller is working towards. |
| Pipe pump status | — | Status | Whether the circulation pump is running. |
| Pipe servo position | % | Live | Current position of the mixing valve (0 = all cool return water, 100 = all hot boiler water). |
| Pipe servo calculated position | % | Calculated | Target valve position the controller is aiming for. |
| GrowPipe measurement | °C | Live | Actual water temperature in the grow pipe (under-crop heating circuit). |
| GrowPipe c-setpoint | °C | Calculated | Target temperature for the grow pipe circuit. |
Shows the live position and status of shade or energy screens. Screen A is typically the primary shade screen; Screen B (when fitted) is a second screen, often used as an energy screen at night.
| Value | Unit | Type | What it shows |
|---|---|---|---|
| Screen status | — | Status | Current screen state: Open, Closing, Closed, Opening, or Blocked (e.g. screen held open by wind or rain override). |
| Screen A / B | % | Live | Actual screen position. 0 % = fully open (retracted), 100 % = fully closed (deployed). |
| Screen c-setpoint | % | Calculated | The target position the controller is working towards, based on radiation, energy mode, or gap control. |
This screen groups the remaining climate measurements: CO2 concentration, solar radiation, the daily light sum used for grow-light control, and the recirculation fan.
| Value | Unit | Type | What it shows |
|---|---|---|---|
| CO2 status | — | Status | Current state of the CO2 system: Off (outside dosing window), Standby (within window, setpoint met), or Dosing (actively injecting CO2). |
| CO2 | ppm | Live | Current measured CO2 concentration inside the greenhouse. |
| CO2 c-setpoint | ppm | Calculated | The CO2 target for the current period, after applying any slope transitions. |
| Signal CO2 | % | Live | Current CO2 dosing valve output level (diagnostic value). |
| Radiation | W/m² | Live | Current solar radiation measured inside or outside the greenhouse. Used by screen, CO2, and lighting control. |
| Radiation c-setpoint | W/m² | Calculated | Filtered or processed radiation value used by the control algorithms. |
| Light status | — | Status | Current state of the grow lights: Off, On (assimilation), or On (day extension). |
| Radiation sum | J/cm² | Accumulated | Total radiation received today (natural + artificial). Resets at midnight. Used by the assimilation lighting programme to decide when enough light has been given. |
| Fan status | — | Status | Whether the recirculation fan is running. |
| Hour count | h | Accumulated | Total running hours of the fan since the last reset. |
Shows the operational status and cumulative running hours of each boiler or heat source. Heater A is the primary unit; Heater B is a second unit that switches on when Heater A alone is not enough to meet demand.
| Value | Unit | Type | What it shows |
|---|---|---|---|
| Heater status | — | Status | Current state of the heater: Off, Standby (waiting for minimum off-time), or Running. |
| Hour count | h | Accumulated | Total hours this heater has been running since the last reset. Useful for scheduling maintenance intervals. |
The SC400 controls the greenhouse temperature using up to five time-based periods throughout the day. Each period has its own temperature target. The system transitions smoothly between periods using configurable slope rates. Period 1 is always active and serves as the base period when multiple periods are not configured.
This screen sets the target temperature for Period 1 — the primary setpoint that the greenhouse heating and ventilation system works to maintain. When only one period is used, this is the single target temperature for the entire day. When multiple periods are enabled, Period 1 is the fall-back period that applies whenever no other period is active (typically the night period).
| Setting | Range | Default | What it does |
|---|---|---|---|
| Temperature | −15.0 to 45.0 °C | 22.0 °C | The inside temperature target for this period. The heating system activates when the measured temperature drops below this value; ventilation opens when it rises above it. Set this to the temperature you want the greenhouse to maintain during this period. |
| Min. pipe temperature pipe heating only | 0.0 to 90.0 °C | 0.0 °C | Forces the heating pipe to stay at or above this temperature during this period, even if the air temperature is already at setpoint. This is useful for root-zone heating or preventing condensation. Set to 0 °C to leave the pipe temperature unforced. |
| Humidity humidity sensor only | 0.0 to 100.0 % | 80.0 % | The target relative humidity for this period. Ventilation opens further if humidity exceeds this value, and the fog system can activate if humidity is significantly below it. 80 % is a typical starting point for most crops. |
| Time method multi-period mode only | Off / Astro Sunrise / Astro Sunset / Absolute | Astro Sunrise | Determines how the start time for this period is defined. Choose Off to disable the period. See the time method table below for details. |
| Start time to sunrise Astro Sunrise only | −4:00 to +4:00 h:m | +00:00 | Number of hours and minutes before (negative) or after (positive) sunrise at which this period becomes active. Example: −01:00 starts the period one hour before sunrise. The actual clock time changes automatically with the season. |
| Start time to sunset Astro Sunset only | −4:00 to +4:00 h:m | +00:00 | Same as above but measured relative to sunset. Useful for setting an evening temperature that tracks the end of the natural light period. |
| Start time Absolute only | 00:00 to 23:59 | 00:00 | A fixed clock time at which this period starts every day, regardless of season. Use this when you want a consistent schedule that does not shift with sunrise or sunset. |
Time method options:
| Option | When to use it |
|---|---|
| Off | The period is disabled and will never activate. Use this to skip a period you do not need. |
| Astro Sunrise | The period starts relative to the calculated sunrise. Recommended for most growers because the transition follows the natural light cycle automatically throughout the year. |
| Astro Sunset | The period starts relative to sunset. Useful for an evening period that matches the end of the day-light period. |
| Absolute | The period starts at a fixed clock time. Use this only when the schedule must be independent of the season, for example for supplemental lighting programmes with fixed hours. |
This screen controls how the setpoint transitions between periods and when temperature alarms are triggered. These settings apply to all five periods.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Rel temp alarm +/- | 1.0 – 25.0 °C | 5.0 °C | An alarm is raised if the measured temperature deviates more than this amount above or below the calculated setpoint. For example, with a setpoint of 22 °C and an alarm of 5 °C, an alarm fires if the temperature goes below 17 °C or above 27 °C. |
| Slope Up | 0.0 – 20.0 °C/h | 0.0 | Maximum rate at which the setpoint may rise when switching to a warmer period. A value of 2.0 °C/h means the setpoint increases by no more than 2 °C per hour, giving a gentle warm-up. Set to 0 to switch instantly. |
| Slope Down | 0.0 – 20.0 °C/h | 0.0 | Maximum rate at which the setpoint may fall when switching to a cooler period. Works the same way as Slope Up but for decreasing transitions. |
| Rel humidity alarm +/- humidity sensor only | 1.0 – 75.0 % | 5.0 % | An alarm is raised if the measured humidity deviates more than this percentage from the humidity setpoint. |
Period 2 defines a second temperature target that becomes active at a configured time. When the Time method is set to Off, this period is disabled and has no effect. The setpoint and start-time fields are greyed out when the period is off.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Time method | Off / Astro Sunrise / Astro Sunset / Absolute | Astro Sunrise | Selects how the start time is defined, or disables this period entirely. See Period 1 for a full description of each option. |
| Temperature | −15.0 – 45.0 °C | 12.0 °C | The temperature target while this period is active. |
| Min. pipe temperature pipe heating only | 0.0 – 90.0 °C | 0.0 °C | Minimum pipe temperature during this period. See Period 1 for details. |
| Humidity humidity sensor only | 0.0 – 100.0 % | 80.0 % | Humidity target during this period. |
| Start time to sunrise | −4:00 – +4:00 | +00:00 | Offset from sunrise at which this period activates (Astro Sunrise mode only). |
| Start time to sunset | −4:00 – +4:00 | +00:00 | Offset from sunset at which this period activates (Astro Sunset mode only). |
| Start time | 00:00 – 23:59 | 12:00 | Fixed daily start time (Absolute mode only). |
Period 3 has the same structure as Period 2. All settings work identically — refer to Period 2 for full descriptions. A typical use is a mid-morning period with a slightly higher temperature once the crop has warmed up after sunrise.
Period 4 has the same structure as Periods 2 and 3. All settings work identically — refer to Period 2 for full descriptions. Typically used for an afternoon or early-evening temperature target.
Period 5 is the last available period and works identically to Periods 2–4. All settings and options are the same — refer to Period 2 for full descriptions. Typically used for a late-evening or night cool-down target.
The ventilation system opens and closes ridge windows to control temperature and humidity. The controller calculates a target opening percentage every minute and drives the window motors towards it. Wind speed and direction are taken into account to protect the structure.
These four settings define the core behaviour of the ventilation controller: when it starts to open and how quickly it responds to temperature changes.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Temperature addition | 0.0 – 20.0 °C | 2.5 °C | The number of degrees above the current temperature setpoint at which the windows start to open. For example, if the setpoint is 20 °C and the addition is 2.5 °C, ventilation begins opening when the temperature reaches 22.5 °C. A larger value means the greenhouse runs warmer before windows open. |
| P-Band | 0.5 – 25.0 °C | 5.0 °C | The proportional band of the ventilation controller. The window opens from 0 % to 100 % as the temperature rises across this band above the opening threshold. A narrow P-Band (e.g. 2 °C) gives a more aggressive response; a wide band (e.g. 10 °C) gives a slower, smoother response. |
| Damping outside temp | 0.1 – 80.0 °C | 20.0 °C | Compensates for hot outside air. If the outside temperature is high, fully open windows would bring in hot air and overshoot the setpoint. This value limits how far the windows open when the outside temperature is close to the inside setpoint. A larger value means less compensation (windows open more freely). |
| Reaction of window | Old / Slow / Normal / Fast | Normal | Controls the speed of the ventilation motor response. Slow makes small corrections at long intervals, reducing wear and preventing hunting. Fast makes larger corrections more frequently, useful when temperature changes are rapid. Old uses the original algorithm for backwards compatibility. |
These two settings fine-tune how sensitive the ventilation controller is to small changes, preventing unnecessary motor movement.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Dead zone | 0.0 – 35.0 % | 1.0 % | The minimum change in calculated opening before the motor is commanded to move. If the new calculated setpoint is within this percentage of the current position, the motor stays still. This prevents constant small adjustments that cause wear without meaningfully affecting the climate. A value of 1 % is a good starting point. |
| Calculation interval | 1 – 20 min | 1 min | How often the controller recalculates the ventilation setpoint and potentially commands the motor. A longer interval (e.g. 5 min) gives the temperature more time to stabilise after a window move before another correction is made, reducing hunting in slow-responding greenhouses. |
When humidity rises above the setpoint by more than the configured difference, the ventilation windows open to let moist air out. This screen sets how much extra the windows can open for humidity removal, independently of the temperature control.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Humidity diff | 0.0 – 100.0 % | 0.0 % | The humidity must exceed the period setpoint by at least this amount before ventilation opens for humidity removal. For example, if the humidity setpoint is 80 % and this value is 5 %, humidity ventilation activates above 85 %. Set to 0 to disable humidity-driven ventilation. |
| Max Opening | 0 – 100 % | 0 % | The maximum additional window opening allowed for humidity control. The windows will not open further than this value purely for humidity purposes, even if humidity remains high. This prevents excessive cold air from entering on cold days when humidity is also high. |
Wind can damage open windows or create uneven ventilation. These settings reduce the window opening proportionally as wind speed increases, and let you sync windows to a known closed position once per day.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Start Wind Trajectory | 0.0 – 17.1 m/s | 1.5 m/s | The wind speed at which the controller begins reducing the window opening. Below this speed, wind has no effect on the ventilation setpoint. |
| End Wind Trajectory | 0.0 – 17.1 m/s | 8.0 m/s | The wind speed at which the maximum reduction has been applied. Between Start and End, the reduction increases linearly. Above End, the maximum reduction is held constant. |
| Max. Vent. decrease Wind | 0 – 100 % | 70 % | The maximum amount by which wind can reduce the calculated ventilation setpoint. For example, if the temperature demands 80 % opening and this value is 70 %, the maximum reduction is 56 % (70 % of 80 %), leaving at least 24 % open. |
| Sync window to 0% at | −4:00 – +4:00 (sunset offset) | +00:00 | Once per day, at this time relative to sunset, the controller drives all windows to fully closed to recalibrate the motor position counter. This corrects any drift that builds up over the day. Set to 0 to sync at sunset. |
| Only sync window below | 0 – 100 % | 10 % | The sync only happens if the calculated setpoint is at or below this percentage at the sync time. This prevents a forced close when the greenhouse still needs ventilation (e.g. on a hot evening). |
| Use slow wind direction | No / Yes | No | When set to Yes, the controller uses a heavily filtered (slow-responding) wind direction signal to decide which side is leeward and which is windward. This prevents the sides from switching rapidly when the wind direction is fluctuating. |
The leeward side is the window on the sheltered side of the greenhouse (away from the wind). Because it is protected, it can generally open further than the windward side without risk of damage. These settings define the position limits that apply to the leeward window under different weather conditions.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Abs. Storm Position | 0 – 25 % | 5 % | The maximum opening allowed during a storm condition. Even if the temperature demands more ventilation, the window will not open beyond this position when storm wind speeds are detected. This protects the structure and crop from storm damage. |
| Max. position Rain | 0 – 100 % | 30 % | The maximum opening allowed when rain is detected. Rain entering an open window can damage the crop or cause disease. This limit reduces the opening to keep rain out while still allowing some ventilation. |
| Maximum position | 0 – 100 % | 100 % | The absolute maximum opening under normal (no rain, no storm) conditions. Setting this below 100 % is useful if the window mechanism has a physical limit, or if you want to reduce draughts in sensitive crop areas near the window. |
| Minimum position | 0 – 100 % | 0 % | The window will never close below this position, even when the temperature is at or below setpoint. A small minimum (e.g. 5 %) ensures a permanent base ventilation to prevent stagnant air and disease pressure. |
The windward side faces into the wind and is more exposed. It typically needs tighter position limits than the leeward side. An additional Following setting allows the windward window to track the leeward window proportionally.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Abs. Storm Position | 0 – 25 % | 0 % | Maximum opening during a storm. The windward side is more vulnerable, so this is typically set lower than the leeward storm position — often 0 % to keep the windward window fully closed in a storm. |
| Max. position Rain | 0 – 100 % | 30 % | Maximum opening when rain is detected. Rain drives directly into windward windows, so this is often set lower than the leeward rain limit. |
| Maximum position | 0 – 100 % | 100 % | Absolute maximum opening in normal conditions. Refer to the Leeward description for details. |
| Minimum position | 0 – 100 % | 0 % | The window never closes below this position. Refer to the Leeward description for details. |
| Following | 0 – 100 % | 0 % | When set above 0, the windward window opens to this percentage of the leeward window's position, rather than calculating its own setpoint from temperature. For example, if set to 80 % and the leeward window is at 50 %, the windward window targets 40 %. This is useful when wind direction varies and you want both sides to open together proportionally. |
The heating system uses one or two boilers (Heater A and B) connected to a hot-water pipe circuit. The controller switches heaters on and off based on the temperature setpoint, with configurable minimum on/off times to protect the boiler.
These settings control how and when each boiler switches on and off. The minimum times protect the boiler from short-cycling (rapid on/off switching which causes wear). The deadzone settings stagger the two heaters so they do not both switch on at the same moment.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Minimum ON time | 5 – 90 min | 10 min | Once a heater switches on, it stays on for at least this many minutes before it is allowed to switch off again, even if the setpoint is already reached. This prevents short bursts that waste energy and cause boiler wear. |
| Minimum OFF time | 5 – 90 min | 10 min | Once a heater switches off, it stays off for at least this many minutes before it can switch on again. This prevents the boiler from re-igniting immediately after a short run, which is hard on burner components. |
| Temp deadzone Heater A Heater A only | 0.5 – 10.0 °C | 3.0 °C | Heater A switches on when the measured temperature drops this many degrees below the current setpoint. For example, with a setpoint of 20 °C and a deadzone of 3 °C, Heater A starts at 17 °C. A larger deadzone means the heater waits longer before switching on. |
| Temp deadzone Heater B Heater B only | 0.5 – 10.0 °C | 4.0 °C | Same as Heater A but for the second boiler. Setting Heater B's deadzone larger than Heater A's (e.g. 4 °C vs 3 °C) means Heater B only activates when the temperature has dropped further, making it a backup that only engages when one boiler is not enough. |
The SC400 can control supplemental grow lights in three programmes: Day Extension (extends the photoperiod before sunrise and/or after sunset), Assimilation (adds light when natural radiation is insufficient during the day), and Photo Period (fixed on/off cycles). Only one programme is active at a time.
This screen selects the lighting programme and the global radiation threshold above which lights are switched off to avoid adding unnecessary heat when there is plenty of natural light.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Program | Off / Day Extension / Assimilation / Photo Period | Off | Selects how the lights are controlled. Off disables all grow lights. Day Extension runs the lights for a set duration before sunrise and/or after sunset to extend the daily light period. Assimilation runs lights during the day whenever natural radiation falls below a threshold. Photo Period runs the lights on a fixed repeating on/off cycle, independent of natural light. |
| Power | Group 1 – Group 4 | Group 1 | Selects which group of light rows is used. Each group corresponds to a set of lighting rows configured on the Light Row screen. This allows different intensity levels to be pre-configured and quickly switched between. |
| Disable at radiation | 1 – 1 250 J/cm² | 3 900 J/cm² | When the accumulated daily radiation sum (natural light received today) exceeds this value, the lights are switched off for the rest of the day. This prevents unnecessary electricity use when the crop has already received enough light. Not applicable in Photo Period mode. |
In Day Extension mode, the lights run for a fixed duration before sunrise and/or after sunset to give the crop a longer daily light period. Both periods can be configured independently — use one or both depending on your crop's needs.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Start time to sunrise | −4:00 – +4:00 | +00:00 | When the morning light period begins, expressed as an offset from sunrise. A negative value (e.g. −02:00) starts the lights 2 hours before sunrise. Set to 0:00 to disable the morning extension. |
| Duration (morning) | 00:00 – 23:59 | 00:00 | How long the lights stay on in the morning extension period. The lights switch off after this duration, regardless of sunrise. Set to 0:00 to disable. |
| Start time to sunset | −4:00 – +4:00 | +00:00 | When the evening light period begins, expressed as an offset from sunset. A positive value (e.g. +00:30) starts the lights 30 minutes after sunset. Set to 0:00 to disable the evening extension. |
| Duration (evening) | 00:00 – 23:59 | 00:00 | How long the lights stay on in the evening extension period. Set to 0:00 to disable. |
In Assimilation mode the lights run during the day, but only when natural solar radiation falls below a set threshold. The light period is bounded by configurable sunrise and sunset offsets — outside this window the lights stay off regardless of radiation.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Start time to sunrise | −4:00 – +4:00 | +00:00 | The earliest the assimilation lights may switch on, expressed as an offset from sunrise. A negative value allows the lights to start before sunrise if radiation is already low. Set to 0:00 to allow lights from sunrise onwards. |
| End time to sunset | −4:00 – +4:00 | +00:00 | The latest the assimilation lights may stay on, expressed as an offset from sunset. A negative value (e.g. −01:00) switches the lights off one hour before sunset. Set to 0:00 to allow lights until sunset. |
| Radiation limit | 0 – 1 200 W/m² | 900 W/m² | The solar radiation level below which the lights switch on. When natural radiation drops below this value (e.g. on a cloudy day), the lights activate to compensate. When radiation rises above it again, the lights switch off. A typical value is 700–900 W/m². |
In Photo Period mode the lights cycle on and off repeatedly throughout the day at a fixed rhythm, regardless of natural light levels. This is used for crops that need a specific light/dark pattern to control flowering.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Number of periods | 1 – 100 | 2 | How many complete on/off cycles run per day. For example, with Period On = 1:00 and Period Off = 1:00, one cycle lasts 2 hours. Setting 12 periods gives 12 × 2 h = 24 h of cycling, covering the full day. |
| Period On | 00:05 – 23:59 | 01:00 | The duration each cycle keeps the lights on. The cycle begins at midnight and the first On period starts immediately. |
| Period Off | 00:05 – 23:59 | 01:00 | The duration each cycle keeps the lights off. After each On period the lights switch off for this duration before the next On period begins. |
The recirculation fan keeps air moving inside the greenhouse to even out temperature and humidity gradients. In Auto mode the controller switches the fan on or off based on the difference between inside and outside conditions.
The fan mode and the conditions under which the fan runs in Auto mode are configured here. All settings below Fan mode are only active when Auto is selected.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Fan mode | Off / On / Auto | Off | Off keeps the fan permanently off. On runs the fan continuously. Auto switches the fan on and off based on the conditions configured below. |
| Start time | 00:00 – 23:59 | 12:00 | In Auto mode, the fan will only run between Start time and End time. Outside this window it stays off regardless of temperature or humidity conditions. |
| End time | 00:00 – 23:59 | 12:00 | The time at which the daily fan window closes. After this time the fan switches off until the next Start time. |
| Temperature diff | 0.0 – 45.0 °C | 3.0 °C | The fan switches on when the inside temperature is this many degrees warmer than the outside temperature. This ensures the fan runs when there is a meaningful temperature gradient to equalize, and stays off when inside and outside temperatures are similar. |
| Outside temp off outside sensor only | −45.0 – 0.0 °C | −4.0 °C | The fan switches off if the outside temperature falls below this value, even if the temperature difference condition is met. This prevents cold outside air from being mixed in during very cold weather. |
| Humidity diff | 0.0 – 10.0 % | 4.0 % | The fan also switches on when the inside humidity exceeds the setpoint by this amount. This helps remove excess moisture even when there is no significant temperature difference. |
This second fans screen configures additional conditions that interact with other greenhouse systems. All rows are conditional — they only appear when the relevant hardware or system is active.
| Setting | Range | Default | What it does |
|---|---|---|---|
| On at screen higher screen only | 0 – 100 % | 40 % | The fan switches on automatically when the shade screen is closed beyond this percentage. A closed screen reduces natural air circulation, so the fan compensates to prevent hot spots and humidity build-up under the screen. |
| Off at ventilation higher ventilation only | 0 – 100 % | 40 % | The fan switches off when the ventilation windows are open beyond this percentage. When windows are wide open, natural air movement is sufficient and running the fan would be redundant and noisy. |
| On while fogging fog system only | No / Yes | Yes | When set to Yes, the fan runs continuously while the fog system is active. The fan distributes the fog evenly throughout the greenhouse and prevents it from settling in concentrated pools near the nozzles. |
| Max. CO2 fan on CO2 sensor only | 1 000 – 5 000 ppm | 1 250 ppm | The fan switches on when CO2 exceeds this level. Running the fan when CO2 is high helps distribute CO2 evenly around the crop and prevents pockets of stale air near the floor. |
| Min. CO2 fan off CO2 sensor only | 250 – 4 500 ppm | 350 ppm | Once the fan has switched on due to high CO2, it stays on until CO2 drops below this level. This hysteresis prevents the fan from rapidly switching on and off when CO2 is hovering near the upper threshold. |
The SC400 supports two CO2 control methods. When a CO2 sensor is installed, the system doses to maintain a measured setpoint across up to three time-based periods. When no sensor is present, an interval timer (CO2 Interval) doses for a fixed on/off cycle during the day, using the boiler flue gas as the CO2 source.
This screen appears only on installations without a CO2 sensor, where the boiler flue gas (containing CO2) is routed into the greenhouse. Because there is no feedback measurement, the system doses on a simple timed cycle within a configurable daily window.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Enable AUTO interval | Off / On | On | Switches the timed CO2 dosing on or off. When Off, no CO2 is dosed regardless of the other settings. |
| Start to sunrise | −4:00 – +4:00 | +00:00 | The daily dosing window opens at this offset from sunrise. CO2 will not dose before this time, even if the interval timer is active. |
| End to sunset | −4:00 – +4:00 | +00:00 | The daily dosing window closes at this offset from sunset. CO2 stops dosing at this time regardless of the interval cycle. |
| Dose ON time | 1 – 90 min | 10 min | How many minutes the CO2 valve stays open during each dose cycle. Longer on-times deliver more CO2 per cycle. |
| Dose OFF time | 1 – 90 min | 10 min | How many minutes the CO2 valve stays closed between dose cycles. This gives the CO2 time to distribute through the greenhouse before the next dose. |
| Enable from radiation sensor only | 25 – 1 100 W/m² | 870 W/m² | CO2 dosing only starts when solar radiation is above this threshold. Plants absorb CO2 faster in bright light; dosing in low light or darkness is wasteful. This setting prevents CO2 from being released when the crop cannot use it. |
CO2 dosing uses up to three time-based periods, each with its own setpoint. Period 1 is the base period (typically the main daytime period). The time method and slope settings work exactly like the temperature periods — refer to the Temperature chapter for a detailed explanation of those options.
| Setting | Range | Default | What it does |
|---|---|---|---|
| CO2 Setpoint | 0 – 1 000 ppm | 250 ppm | The CO2 concentration the system will dose to maintain during this period. The controller doses CO2 when the measured level falls below this value. Typical greenhouse enrichment targets are 600–1 000 ppm depending on crop and ventilation rate. |
| Enable from radiation sensor only | 25 – 1 100 W/m² | 870 W/m² | CO2 dosing only activates when solar radiation is above this threshold. Plants absorb CO2 through photosynthesis which requires light — dosing in darkness is wasteful. This setting prevents unnecessary CO2 use at night or during very cloudy periods. |
| Time method | Off / Astro Sunrise / Astro Sunset / Absolute | Astro Sunrise | Determines when this period becomes active. See the Temperature chapter for a full explanation of each option. |
| Start time to sunrise / sunset / absolute | various | +00:00 | The start time of this period, defined as an offset from sunrise, offset from sunset, or a fixed clock time — depending on the Time method selected. |
| Slope Up | 0 – 500 ppm/h | 0 ppm/h | Maximum rate at which the CO2 setpoint may rise when transitioning to this period from a lower setpoint. Set to 0 for an instant switch. |
| Slope Down | 0 – 500 ppm/h | 0 ppm/h | Maximum rate at which the CO2 setpoint may fall when transitioning away from this period to a lower setpoint. Set to 0 for an instant switch. |
Period 2 has the same structure as Period 1. Set Time method to Off to disable this period. All settings work identically to Period 1 — refer there for full descriptions. A typical use is a higher CO2 setpoint (e.g. 800 ppm) during peak growing hours and a lower setpoint at other times.
Period 3 is the third and final CO2 period. It works identically to Periods 1 and 2 — refer to Period 1 for full descriptions. Period 3 defaults to Astro Sunset timing with a setpoint of 0 ppm, making it a convenient end-of-day period that stops dosing after sunset.
This screen contains system-wide CO2 settings that apply regardless of which period is active. It also links CO2 dosing to the heating system, since many installations use boiler flue gas as the CO2 source.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Percent heaters to use | 25 – 100 % | 100 % | When the boiler flue gas is used as the CO2 source, this setting limits how much of the heating output can be "borrowed" for CO2 dosing. For example, setting 75 % means only 75 % of the total heating capacity will be used for CO2 production — the rest remains available purely for heating. This prevents over-heating the greenhouse when CO2 demand is high. |
| CO2 dead zone CO2 sensor only | 25 – 750 ppm | 30 ppm | The CO2 level must fall this many ppm below the setpoint before dosing starts. Once dosing starts, it continues until the setpoint is reached. This prevents the dosing valve from opening and closing rapidly when CO2 is hovering near the setpoint. |
| CO2 Alarm CO2 sensor only | 1 000 – 8 000 ppm | 2 000 ppm | An alarm is triggered if the measured CO2 concentration rises above this level. Excessively high CO2 (above ~2 000 ppm) can indicate a dosing malfunction or inadequate ventilation and may be harmful to workers entering the greenhouse. |
| Max. temperature | 15.0 – 50.0 °C | 35.0 °C | CO2 dosing is automatically suspended if the inside temperature exceeds this value. When it is very hot, the ventilation windows need to be open to cool the greenhouse — open windows allow CO2 to escape, making dosing pointless and wasteful. |
The pipe heating system circulates hot water from the boiler through pipes inside the greenhouse. A motorised mixing valve blends hot and return water to maintain the pipe at the correct temperature. The controller uses a proportional-integral (PI) algorithm to position the valve.
These settings control the behaviour of the hot-water pipe circuit and its mixing valve. They are technical parameters that rarely need to be changed once the system is commissioned.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Heating addition | −35.0 – −0.1 °C | −5.0 °C | The pipe heating circuit starts working when the air temperature falls this many degrees below the current air temperature setpoint. For example, with a setpoint of 20 °C and an addition of −5 °C, the pipe circuit activates when the air temperature drops to 15 °C. A smaller negative value (e.g. −2 °C) makes the system respond earlier. |
| Max. pipe temperature | 30.0 – 90.0 °C | 60.0 °C | The absolute maximum temperature the pipe is allowed to reach. This protects the pipes, fittings, and any crop in contact with the pipes from damage due to excessive heat. |
| Pipe / Heating ref. | 2.0 – 50.0 °C | 35.0 °C | The reference temperature difference used to scale the pipe temperature setpoint relative to the air setpoint. This is an installation-specific calibration value that links the pipe curve to the actual heat output of the system. |
| Pipe temp I-Time | 0 – 10 000 s | 30 s | The integration time of the pipe temperature controller. A longer I-Time makes the controller slower to respond to temperature errors but avoids overshooting the pipe setpoint. |
| Valve I-Time | 0 – 10 000 s | 30 s | The integration time of the mixing valve position controller. This controls how quickly the valve moves to reach the target position. A longer time results in slower, smoother valve movement. |
| Valve P-Band | 1.0 – 30.0 °C | 10.0 °C | The proportional band of the mixing valve controller. The valve moves from 0 % to 100 % as the pipe temperature error grows across this band. A wider P-Band gives smoother but slower valve response. |
When humidity is high, a warmer pipe can help drive moisture out of the crop canopy. These two settings allow the minimum pipe temperature (set per period) to be automatically raised when the measured humidity exceeds its setpoint.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Humid. inf. min. pipe | 0.0 – 10.0 °C | 10.0 °C | The scale factor that determines how strongly high humidity raises the minimum pipe temperature. A value of 10.0 °C means that when humidity is at its maximum deviation above setpoint, the minimum pipe temperature is raised by up to the Humid. max. addition value. A lower value reduces the influence of humidity on pipe temperature. |
| Humid. max. addition | 0.0 – 20.0 °C | 10.0 °C | The maximum number of degrees that the minimum pipe temperature can be raised due to high humidity. For example, if the period's minimum pipe temperature is 30 °C and this value is 10 °C, the pipe minimum can be raised to at most 40 °C when humidity is very high. |
Grow pipes run close to or under the crop and maintain a lower, more stable water temperature than the main heating pipes. They provide root-zone warmth without overheating the air. The controller uses a mixing valve with PI control to hold the grow pipe at the configured temperature range.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Max. growpipe temp | 20.0 – 39.0 °C | 30.0 °C | The upper limit for the grow pipe water temperature. The mixing valve will never allow the grow pipe to exceed this temperature, protecting the root zone from heat stress. |
| Min. growpipe temp | 20.0 – 39.0 °C | 30.0 °C | The lower limit for the grow pipe water temperature. The controller will maintain at least this temperature in the grow pipe circuit at all times when the system is active, ensuring a minimum level of root-zone warmth even when the air setpoint is already met. |
| Valve I-Time | 0 – 10 000 s | 30 s | The integration time of the grow pipe mixing valve controller. Controls the speed of valve adjustment. Refer to the Heating System screen for a full description. |
| Valve P-Band | 1.0 – 30.0 °C | 10.0 °C | The proportional band of the mixing valve controller. Refer to the Heating System screen for a full description. |
The SC400 controls up to two motorised screens (A and B). Each screen has three independent control modes that work simultaneously: Radiation (shade during bright sunlight), Energy (insulation at night), and Gap (small opening for humidity removal). The screen position is the highest demand from all active modes.
The radiation mode closes Screen A during bright sunlight to protect the crop from heat and light stress. The screen closes proportionally as radiation rises, and opens again as radiation falls. A time window limits radiation control to daylight hours only.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Start to sunrise | −4:00 – +4:00 | +01:00 | The radiation screen control becomes active at this offset after sunrise. Setting +01:00 means the screen will not respond to radiation until one hour after sunrise, giving time for the greenhouse to warm up naturally in the morning. |
| End to sunset | −4:00 – +4:00 | −01:00 | The radiation screen control deactivates at this offset before sunset. Setting −01:00 means the screen opens one hour before sunset, allowing the afternoon sun in as temperatures drop. |
| Radiation above 100% | 0 – 1 200 W/m² | 1 000 W/m² | When radiation rises above this level the screen closes fully (100 %). This is the main shading threshold — set it to the radiation level at which crop heat stress begins. |
| Radiation below 100% | 0 – 250 W/m² | 0 W/m² | When radiation falls below this level the screen opens fully (0 %). This creates a hysteresis gap between the closing threshold and the opening threshold, preventing the screen from continuously opening and closing when radiation fluctuates around the main threshold. Set to 0 to disable hysteresis (screen opens as soon as radiation drops below the closing threshold). |
| Radiation for position | 0 – 1 200 W/m² | 900 W/m² | At radiation levels between Radiation below 100% and Radiation above 100%, the screen moves to a partial position. This value sets the radiation level at which the screen reaches the partial position defined by Screen position. Set to 0 to disable partial positioning (screen is either fully open or fully closed). |
| Screen position | 0 – 100 % | 80 % | The partial screen position used when radiation is at the Radiation for position level. For example, 80 % means the screen is 80 % closed at that radiation level. Between the partial and full thresholds the position is interpolated proportionally. |
This screen only appears on installations with an outside (retractable) shade screen mounted above the greenhouse roof. It defines the weather conditions under which the outside screen must be retracted to prevent wind and rain damage.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Open above windspeed | 0.0 – 33.0 m/s | 12.0 m/s | When wind speed exceeds this value the outside screen is retracted (opened) regardless of radiation, to prevent it from being torn by the wind. Once wind drops below this threshold, normal radiation control resumes. |
| Open when raining | No / Yes | Yes | When set to Yes, the outside screen retracts whenever rain is detected. Rain pooling on a deployed outside screen can cause structural damage. Set to No only if the screen material is designed for outdoor use in rain. |
When Screen A is closed, moisture and heat can build up underneath it. The gap control opens a small slot in the screen to release excess humidity or heat, without fully opening the screen and losing its shading or insulating effect.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Min position | 0 – 100 % | 0 % | The screen will never close below this position, even when no gap is demanded. A small permanent gap (e.g. 5 %) ensures constant low-level ventilation under the screen at all times. |
| Temp difference | 0.0 – 35.0 °C | 5.0 °C | The gap opens when the measured temperature exceeds the setpoint by more than this amount. This prevents overheating under a closed screen on a sunny day. The gap increases proportionally as the temperature excess grows, up to the Max Opening limit. |
| Humidity difference humidity sensor only | 0 – 100 % | 15 % | The gap also opens when humidity exceeds the setpoint by more than this amount. High humidity under a closed screen promotes fungal disease, so a gap is opened to let moist air escape. |
| Max Opening | 0 – 100 % | 25 % | The maximum gap the screen is allowed to open for temperature or humidity relief. Keeping this small (15–25 %) preserves the primary function of the screen while still allowing ventilation. |
The energy screen closes at night to insulate the greenhouse and reduce heating costs. This screen configures when it closes and how it opens temporarily to release heat or humidity build-up during the night.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Time method | Absolute / Astro | Astro | Determines how the energy screen window is defined. Astro uses offsets from sunset (start) and sunrise (end), so the screen automatically follows seasonal day length. Absolute uses fixed clock times that do not change with the season. |
| Start time / Start to sunset | 00:00–23:59 / −4:00–+4:00 | +00:00 (sunset) | When the energy screen begins to close. In Astro mode, 0:00 means closing starts at sunset. A positive offset (e.g. +01:00) delays closing until one hour after sunset, useful if evening temperatures are still high. |
| End time / End to sunrise | 00:00–23:59 / −4:00–+4:00 | +00:00 (sunrise) | When the energy screen opens at the end of the night. In Astro mode, 0:00 means the screen opens at sunrise. A negative offset (e.g. −01:00) opens the screen one hour before sunrise to allow the greenhouse to warm up gradually before daylight. |
| Max. opening time | 0 – 240 min | 30 min | If the temperature or humidity under the closed screen rises too high, the screen opens briefly to ventilate. This setting limits how long each such opening event lasts. After this time the screen closes again even if conditions have not fully recovered. |
| At delta temp | 0.0 – 25.0 °C | 10.0 °C | The screen opens for a ventilation event when the measured temperature exceeds the setpoint by more than this amount while the energy screen is closed. A larger value means the screen tolerates more overheat before opening. Set to 0 to allow opening at any positive temperature deviation. |
| Opening step | 1 – 20 % | 10 % | How far the screen opens during each ventilation event. A small step (e.g. 5 %) releases heat gently; a larger step (e.g. 20 %) ventilates faster but loses more heat. After each step the controller waits to assess the effect before opening further. |
These two settings define the weather conditions under which the energy screen is allowed to close. If either condition is not met, the screen stays open even during the configured energy window.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Below outside temp | −15.0 – 45.0 °C | 10.0 °C | The energy screen only closes when the outside temperature is below this value. If it is warm outside, the insulating screen offers little benefit and may cause overheating. Lowering this threshold (e.g. to 5 °C) means the screen only closes on colder nights, saving heating energy when it matters most. |
| Below radiation | 0 – 500 W/m² | 20 W/m² | The energy screen only closes when solar radiation is below this level. This prevents the screen from closing during the day even if the time window spans daylight hours. A value of 20 W/m² means the screen will not close while there is any meaningful sunlight. |
This screen works identically to the Screen A Gap (radiation) settings but applies specifically when the screen is closed in energy mode (night insulation). The gap settings for radiation and energy modes are independent, allowing different gap behaviour during the day and at night.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Temp difference | 0.0 – 35.0 °C | 5.0 °C | Opens a gap in the energy screen when the temperature exceeds the setpoint by this amount during the night. A smaller gap is typically used at night (compared to daytime) to minimise heat loss while still preventing overheating. |
| Humidity difference humidity sensor only | 0 – 100 % | 15 % | Opens a gap when humidity exceeds its setpoint by this amount during the night. Night humidity build-up under a closed energy screen is a common cause of fungal disease, so a small gap is important. |
| Max Opening | 0 – 100 % | 25 % | The maximum gap allowed during energy mode. Keeping this small (10–25 %) preserves the insulating effect of the screen while still allowing moisture and heat to escape. |
Screen B radiation control works identically to Screen A radiation control. All settings have the same meaning and ranges — refer to Screen A Radiation for full descriptions. Screen B is typically a second shade layer or a screen in a different greenhouse section, and can be configured independently with its own radiation thresholds.
Screen B gap control works identically to Screen A gap control. All settings have the same meaning and ranges — refer to Screen A Gap for full descriptions. Screen B can be given its own gap thresholds if it operates in a different zone or climate condition than Screen A.
The high-pressure fog system sprays very fine water droplets into the greenhouse air. As the droplets evaporate they cool the air and raise humidity simultaneously. The system pulses the fog pump on and off — the ratio of on-time to off-time is controlled proportionally based on the demand. There are two trigger mechanisms: temperature-based (cool the air) and humidity-based (raise humidity), both operating independently within the same daily time window.
The fog system has two independent trigger conditions. Either condition alone is enough to activate the fog pump. Each trigger has a guard limit on the other climate variable to prevent fogging in unsuitable conditions.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Start to sunrise | −4:00 – +4:00 | +01:00 | The fogging system is only allowed to run within a daily time window. This offset defines when the window opens relative to sunrise. Fogging is typically only useful during daylight hours when evaporation is driven by heat and radiation. |
| End to sunset | −4:00 – +4:00 | −01:00 | When the daily fogging window closes, relative to sunset. Fogging before sunset allows moisture to dry before the cooler night air arrives. |
| Temperature diff | −10.0 – 35.0 °C | 5.0 °C | The temperature trigger activates fogging when the measured inside temperature exceeds the current setpoint by more than this amount. For example, with a setpoint of 24 °C and a diff of 5 °C, fogging starts when the temperature reaches 29 °C. Set to 0 (Off) to disable temperature-based triggering entirely. |
| Humidity limit active when Temp diff > 0 | 0 – 50 % | 25 % | A safety guard for the temperature trigger. Even if the temperature is above the trigger threshold, fogging will not start if the humidity is already within this percentage below its setpoint. This prevents over-humidification when trying to cool an already humid greenhouse. |
| Humidity diff | 0.0 – 10.0 % | 4.0 % | The humidity trigger activates fogging when the measured humidity falls more than this percentage below the humidity setpoint. For example, with a setpoint of 80 % and a diff of 4 %, fogging starts when humidity drops to 76 %. Set to 0 (Off) to disable humidity-based triggering. |
| Temperature limit active when Humidity diff > 0 | −20.0 – 0.0 °C | −2.5 °C | A safety guard for the humidity trigger. Fogging will not start if the temperature is already this many degrees below the setpoint, even if humidity is low. Fogging into a cold greenhouse causes condensation problems rather than solving humidity issues. |
These settings define how the fog pump behaves once a trigger condition is active. The pump does not run continuously — it pulses on and off, with the on-time increasing proportionally as demand grows.
| Setting | Range | Default | What it does |
|---|---|---|---|
| Radiation limit | 0 – 1 200 W/m² | 800 W/m² | The fog system only operates when solar radiation is above this level. High radiation provides the energy to evaporate the fine droplets — without sufficient radiation the droplets may not evaporate quickly enough, causing condensation on plants and structures. On overcast days when radiation is low, fogging is suppressed automatically. |
| Min pulse time | 1 s – max | 10 s | The minimum duration of each pump-on pulse. Even at low demand, the pump runs for at least this many seconds to ensure a complete fog burst is produced. Very short pulses can be ineffective if the nozzles need time to build pressure. |
| Max pulse time | 1 s – max | 20 s | The maximum duration of each pump-on pulse at full demand. The actual pulse time scales between Min and Max proportionally with the demand level. A wider range between Min and Max gives finer control over the amount of water delivered. |
| P-Band | 1 – 1 000 % | 50 % | The proportional band of the fog controller. At a temperature or humidity error equal to the P-Band value, the fog pump runs at 100 % duty (maximum pulse time). A smaller P-Band gives a more aggressive response to small deviations; a larger P-Band gives a gentler, more gradual response. |
Individual light rows (circuits) can be assigned to groups 1–4. The active group is selected on the main Light settings screen. This allows pre-configured power levels — for example Group 1 = full intensity, Group 2 = 50 % intensity — that can be switched quickly without re-programming each row.
Each row that is wired to this light controller appears here. For each row you select which power group it belongs to. Rows set to the same group switch on and off together. Only rows physically connected to this controller appear on the screen.
| Setting | Options | Default | What it does |
|---|---|---|---|
| Group 1 – 4 (per row) | Off / 25 % / 50 % / 75 % / 100 % | Off | Assigns this light row to a power group and sets its intensity level within that group. Off means the row is never switched on by the lighting programme. Selecting a percentage (25–100 %) assigns the row to the corresponding power group. When the active group is selected on the main Light screen, all rows in that group switch on at their configured intensity. |
This screen shows the remaining light rows (if more than four are installed). The settings work identically to Groups 1–4 — refer to that screen for a full description. Rows only appear if they are physically connected to the controller.
The alarm screen configures which conditions trigger notifications. Each alarm can be set to Off (no notification), Warning (logged but no output), or Alarm (logged and activates the alarm output/relay). Only alarms for hardware that is actually installed appear on the screen.
Each alarm condition can be independently configured. The alarm thresholds themselves (e.g. how many degrees above setpoint triggers a temperature alarm) are set elsewhere — typically on the relevant settings screen such as Temperature Periods. This screen only controls what happens when the threshold is crossed.
| Alarm | Options | Default | What it monitors |
|---|---|---|---|
| Temperature alarm temperature sensor only | Off / Warning / Alarm | Off | Activates when the measured temperature deviates from the setpoint by more than the Rel temp alarm value configured on the Temperature Periods screen. Use Alarm to trigger the external alarm output (relay) so staff are notified, for example by a SMS module or audible buzzer. |
| Sensor defect | Off / Warning / Alarm | Off | Activates when any connected sensor returns an out-of-range or disconnected reading. A faulty sensor causes the controller to work without feedback, which may result in incorrect heating or ventilation. This alarm should generally always be enabled. |
| CO2 too high CO2 sensor only | Off / Warning / Alarm | Off | Activates when the measured CO2 concentration exceeds the CO2 Alarm level set on the CO2 System screen. Excessively high CO2 can indicate a dosing valve stuck open or inadequate ventilation, and high levels may be harmful to workers inside the greenhouse. |
| Humidity alarm humidity sensor only | Off / Warning / Alarm | Off | Activates when the measured humidity deviates from the setpoint by more than the Rel humidity alarm value configured on the Temperature Periods screen. Persistent high humidity promotes fungal disease; persistent low humidity stresses the crop. |