Having a PDA as a base means that in addition to being a translator, it can also hold an AI guidance program.
They're typically just used to help with interplanetary navigation but can also act as a sort of digital advisor while traversing new places. It's very useful to those who are new to space travel.
Hey I'm not new! I've just never visited the Vertex until now!
I've done space travelling... so many times!
And yet you've never needed a translator until now? How extraordinarily convenient.