The 1-10v ports on the P4 allow you to control multitude devices that have a 1-10v connection. You can plug it directly into the 1-10v connection if a compatible GHL cable exist or your good with a soldering iron and making your own cable, or you can even use the GHL LBF-AP break out box which then provides the interface to the 1-10v connection.
I have a few things running now on the 1-10v connection. On my second tank my Tunze Pumps and RedDragon Return Pump, Breeze and Mitras Simulation bars are all on the 1-10v connections. On my Main tank my Aybzz Return pump is plugged into the 1-10v connection, and my Kessil light through an LBF-AP breakout box.
The configuration could not be easier, so lets start with where do I see the 1-10v connections?
If your using the desktop software it is from within the System menu.
As you can see above I have a few things utilizing the 1-10V on this tank, a GHL Breeze to help cool the tank (Works Great), My Simulation Light Bars which I use for Moon Light on the tank and my Tunze and Return Pump. The reason why your seeing the word Expansion is for me to know where I have them plugged into which device the P4 of the Expansion Box.
Fear not you do not need to use the Desktop App at all in the configuration of the port of apply the functions and configure the functions of the port, you have all the options on the P4 Device itself in the web interface and the GCC App also :)
Once you have the Device connection to the Line Port(1-10v) (Yellow Port on the P4) you configure that line port with the options you want to use to control the device.
If the Tunze pump has a 1-10v controllable connection you need a one GHL Tunze Cable per Tunze pump and if your running multiple Tuzne Pumps you need then a Tunze 1 and a Tunze 2 Cable which allows you to control two Tunze Pumps per L port.
Tunze 1 cable:
https://www.aquariumcomputer.com/usa/product/profiluxtunze1/
Tunze 2 cable:
https://www.aquariumcomputer.com/usa/product/profiluxtunze2/
Then the cable that splits the 1-10v port into two connections:
https://www.aquariumcomputer.com/usa/product/yl2-1/
The GHL Tunze cable plugs into the 1-10V Port of the Tunze Controller
Plug the other end into the Yl2 Cable or directly into the P4.
Then it time to configure what you wish the Tunze pumps to do.
The steps below are the same no matter what your trying to control now on the 1-10V you must choose the function that will control the 1-10v device.
For my Tunze I am selecting a Stream Group and apply into to a Stream Group Number.
Once you do that you then go into the stream group and set the type of effect your looking for, below are some shots of my stream group configuration.
To see how stream groups work a great explanation is on the GHL website
https://www.aquariumcomputer.com/profilux-4-making-waves/
You can also get creative with illumination channels shown on this thread :). If your going to use Illumination channel make sure you set the Illumination channel as dimmable.
https://www.reef2reef.com/threads/gyre-programming-question.507010/#post-5380490
Using an illumination channels on the 1-10V port allow you to simulate a gyre type effect with one pump ramping up on one side of the tank as one is ramping down.
If you have a GHL LB-AF module you plug that into the L port which and program it the same way, choose your function then go specifically into that function and program the function for the effect your looking for.