Questions about virtual signals.

[Chocki]

I am learning as I go and making a mod that just adds virtual signals. I was trying to figure out a way to link them to researching a technology. So that you would have to research "Extra signals 1" before you can see and use the signals.

After digging around, I noticed the virtual signals don't seem to have a way to be linked like I want. Am I correct that the player technically has the virtual signals from the start of the game, just doesn't have any access to the menu to notice. As it there is no mention of virtual signals in the technology.lua, and virtual signals don't have a "required tech" tag like recipes.

Thanks for your time.