Summary #
Programmable Logic allows you to define custom switching conditions by combining existing system states using logical and time-based functions. Each logic gate takes one or two inputs — such as a timer, sensor control, or another gate’s output — applies a function, and produces an output signal that can be assigned to switch channels. This makes it possible to create conditions that go beyond what individual functions support on their own, such as combining multiple sensors, adding time delays, or building multi-step control sequences.
Applies to #
- ProfiLux 4 Series (incl. Industrial Line / IL)
- ProfiLux 3 Series
- Software:
- GHL Connect (App, Webinterface, myGHL)
- GHL Control Center
Configuration #
Open Programmable Logic via Programmable logic in GHL Connect or GHL Control Center.
All programmable logic entries are listed with their current settings. Open an entry for editing by double-clicking it or selecting it and clicking Edit (GHL Control Center), or by tapping it in the list (GHL Connect).
Input 1 and Input 2 #
Each entry has one or two inputs depending on the selected function. Input 1 and Input 2 are configured identically. In GHL Control Center, click Change to edit an input’s settings.
For each input, select a Function — the signal source that contributes an ON/OFF state to the gate — and where applicable a parameter to link it to a specific circuit or instance. An Invert option reverses the input signal before it reaches the gate.
Lighting:
- Illumination: ON when the assigned illumination channel is active (brightness above 0%). Select the illumination channel index.
- Variable illumination: Follows a variable illumination schedule. Select the variable illumination index.
Pumps & Dosing:
- Pump: ON when the assigned pump group program is active. Select the pump index.
- Dosing pump: ON during dosing events. Select the dosing pump index.
- Magnetic stirrer: Follows the stirrer’s schedule. Select the stirrer index.
Level & Water:
- Fill water / Drain water / Fill water (AWC only) / Fill water (ATO only) / Water change: ON when the corresponding level control action is active. Select the level control circuit.
Maintenance & System:
- Maintenance: ON during the selected maintenance period. Select the maintenance index.
- Filter: Normally ON, switches OFF during the selected feed pause. Select the feed pause index.
- Timer: Follows a timer’s schedule. Select the timer index.
- Programmable logic: Uses the output of another gate as input, allowing gates to be chained. Select the gate index.
- Digital input: Follows the state of a digital input. Select the input index.
Alarms:
- Flow sensor alarm: ON when the selected flow sensor triggers an alarm. Select the sensor index.
- General alarm: ON when any alarm in the system is active.
Simulations:
- Thunder: ON briefly with each lightning flash during a thunderstorm simulation.
- Thunderstorm: ON for the entire duration of a thunderstorm simulation.
- Rainy days: ON on days configured as rainy days in the Simulation settings.
KH Director:
- KH-value control upwards (increase) / KH-value control downwards (decrease): Follows the KH Director’s control output. Requires a connected KH Director.
Simple:
- Always on / Always off: Permanently ON or OFF.
Sensors (added dynamically based on connected sensors): Each connected sensor appears with its own sub-functions. Temperature and air temperature sensors offer Chiller, Heater, Substrate heater, PTC, and Alarm. All other sensor types offer Control upwards (increase), Control downwards (decrease), and Alarm.
Function #
The function defines how the inputs are combined to produce the gate’s output. For detailed descriptions and timing diagrams of each function, refer to the Programmable Logic instructions document listed in the Downloads section.
Logical functions (two inputs):
- AND: Output ON only when both inputs are ON.
- OR: Output ON when at least one input is ON.
- NAND: Output OFF only when both inputs are ON; ON in all other cases.
- NOR: Output ON only when both inputs are OFF.
- Equal: Output ON when both inputs have the same state.
- Unequal / XOR: Output ON when the inputs have different states.
- SR-Flipflop: Input 1 acts as Set, Input 2 as Reset. When Set goes ON, the output turns ON and remains ON even after Set goes OFF again. The output turns OFF only when Reset goes ON.
Logical function (one input):
- NOT: Output is always the inverse of Input 1. No second input or time parameter.
Time functions (one input + time): These functions use Input 1 and a configurable time value (1 s – 28800 s). Input 2 is not used.
- Pulse: When Input 1 switches ON, the output turns ON for the set time, then switches OFF — regardless of the input’s state.
- Delayed on: When Input 1 switches ON, the output follows after the set delay. When Input 1 switches OFF, the output follows immediately.
- Delayed off: When Input 1 switches ON, the output follows immediately. When Input 1 switches OFF, the output follows after the set delay.
- Cyclic: While Input 1 is ON, the output alternates ON and OFF at the set interval. When Input 1 is OFF, the output is OFF.
Examples #
Skimmer follows timer schedule but turns off during feed pause (AND) #
A skimmer is controlled by a timer. During a feed pause the skimmer should also switch off, even if the timer is currently in its ON phase. Open a Programmable Logic entry and set the function to AND: Input 1 = Timer (the skimmer timer), Input 2 = Filter (the relevant feed pause). The output is ON only when the timer is active AND no feed pause is running. Assign the entry to the skimmer’s switch channel.
Skimmer reacts to either of two feed pauses (AND) #
Two separate feed pauses are configured — for example, one manual and one timer-triggered. The skimmer should switch off when either one is active. Set the function to AND: Input 1 = Filter 1, Input 2 = Filter 2. The Filter function is normally ON and goes OFF during its assigned feed pause, so the output switches OFF as soon as either feed pause activates. Assign the entry to the skimmer’s switch channel.
Stop an ATO dosing pump during maintenance (AND + Invert) #
A dosing pump head is used as an ATO pump. During maintenance it should be forced off, even if the ATO function would normally activate it. Set the function to AND: Input 1 = Fill water ATO only (the ATO control circuit), Input 2 = Maintenance (the relevant maintenance program) with Invert enabled. The output is ON only when the ATO is calling for water AND maintenance is not active. Assign the entry to the pump’s switch channel.
Notes #
- Chaining entries: Any entry’s output can be used as an input for another entry by selecting Programmable logic X as an input function, enabling multi-step logic.
- Assignment: An entry’s output is used by assigning the Programmable Logic function with the corresponding index in Switch Channels.