e.g. the machine is a big box. You can "start" the machine once and "end" it once. When you "start" the machine it instantaneously teleports everything inside it from when you "end" the machine.
If you "start" the machine and break it before "end"ing it, nothing gets sent through, or there's a giant explosion, or the universe collapses, etc.
Alternatively, you can "receive" and "send" any number of times on the machine. But every time you "receive" you get a unique ID, and you can only "send" to that ID once.
e.g. the machine is a big box. You can "start" the machine once and "end" it once. When you "start" the machine it instantaneously teleports everything inside it from when you "end" the machine.
If you "start" the machine and break it before "end"ing it, nothing gets sent through, or there's a giant explosion, or the universe collapses, etc.
Alternatively, you can "receive" and "send" any number of times on the machine. But every time you "receive" you get a unique ID, and you can only "send" to that ID once.