What is the Difference Between the WE7271 and the WE7272 Digitizer Modules?

The input connectors are different, the WE7271 Digitizer Module has a clamp type terminal, and the WE7272 Digitizer Module has a BNC terminal. Also, the maximum common mode voltage, and maximum voltage between channels vary in their specifications between the two instruments (the WE7272 is lower). Please see the specification sheet for more details.