The IBM 270x family, of which the 2701 Data Adaptor Unit was a member of, was an early example of communication controller and worked with the IBM 360 and 370. The 2701 "greatly expands the input/output capabilities of the IBM System/360"  by helping to interface to and control information flow from peripherals like the IBM 7701 Magnetic Tape Transmission Unit. The IBM 2701 was introduced in 1964 and replaced by the IBM 3704 in 1972.
|Public domain image from SDASM Archives|
 Barry Wilkinson & David Horrocks, Computer Peripherals (Edward Arnold, 1987) p. 281
 IBM 2701 Data Adaptor Unit Principles of Operation (IBM, 1965) p. 5