Transfering Data From Digital Equipment to PC

I'm trying to transfer data into Rasberry Pi from any kind of digital electronic equipment. Let's say Digital Multimeter. When you measure, it displays you a Current but if it is possible to capture that result into some file or table in any PC for further working with those data? Let's say automatic statistics of current//power of all devices in your home.

So far I have only idea but if anybody could help on that I would appreciate and cooperate with him.