** UPDATE - Trigger boxes are not needed anymore when working with Canon cameras. The details below are applicable only if you're using Nikon cameras or the newer Canon M6 Mark II. For the rest, precise usb triggering is possible, straight from the computer to the usb-hubs to the cameras **
As of version 1.9.0, Xangle Camera Server offers the ability to control one Esper Triggerbox via USB.
In order to use this feature, you must follow this "getting-started" guide provided by Esper.
You can then use the Trigger Box Controller software to program each box individually (Blue mode)
Connect to the trigger box with the "Connect" (1) and don't forget to save the "recipe" (2). Optionally, you can also rename the box. If you have several boxes linked together, enable the "link".
When the programming is done, close the program and launch xangle-server (> 1.9.0), with only the "master" box being connected.
In the dashboard, you should have the option to change the "control mode" to trigger box
The name in between the brackets should correspond to the name you set with the Esper's software.
Once this is option is selected, you can use your preferred trigger method in the software and the signal will be sent to your triggerbox.