Per the [Star Wars: Absolutely Everything You Need to Know][1] factbook

[![enter image description here][2]][2]

It's also mentioned in the junior novelisations for Force Awakens and the prequel novel.

> *The lead TIE cracked, then flared, then just wasn’t there anymore. He
> broke to his right, yanking back on the stick. BB-8 sang a burst of
> binary, and then Poe was behind a second TIE.*

> <sub><sup>[Before the Awakening][3]</sub></sup>

and

> *She grabbed her staff from the walker, then ran out into the desert,
> heading toward the sound. It repeated, the same tone at a precise
> rate. Binary, from the sound of it. The language of droids.*

> <sub><sup>[Force Awakens: Junior novelisation][4]</sub></sup>


  [1]: http://starwars.wikia.com/wiki/Star_Wars:_Absolutely_Everything_You_Need_to_Know
  [2]: https://i.sstatic.net/a1e2R.png
  [3]: http://starwars.wikia.com/wiki/Before_the_Awakening
  [4]: http://starwars.wikia.com/wiki/Star_Wars:_The_Force_Awakens_(junior_novelization)