What is Silent Linking? How is it done? Why is it done? What are the advantages?

Silent linking is the ability for a PC or other device to communicate with a calculator without it being in a special receive mode -- which means you can communicate with it while it's at the homescreen or various other places in the OS.

While on, the calculator's OS basically sits in a constant loop -- one of the things it does in this loop is (obviously) wait for a key to be pressed, and then acts on it (like opening a menu, entering a character on the homescreen, etc.). Another thing it does is see if there's any link activity going on with either the I/O or direct USB ports. If so, it handles it.

When TI Connect, TiLP, etc. communicate with a calculator that supports silent linking, it sends requests to the calculator which the OS then responds to.

It's convenient because you can force the calculator to do things without any interaction (such as sending files, receiving files, remote control of it, etc.), and because you don't have to go into any sort of special receive mode (it can be anywhere in the OS, or even off -- the calculator will turn itself on if it detects link activity).

*Impressed* There isn’t any special way of doing it without the software you mentioned?

It can be done using anything you want -- you can even write some calculator code to control another calculator through silent linking.

The protocol for I/O and USB are different, but well documented.

The software is built into your calculator's OS; you don't need anything special at all (except for whatever external thing that you want to speak the silent link protocol). This is an example of silent linking in action: