This signal generator consists of a Schmitt trigger and an integrator. The output of the Schmitt trigger part opamp (opAmp1) is a rectangular signal with the amplitude VAmp and the frequency f. The output of the integrator part opamp (opAmp2) is a triangular signal of also the amplitude Vamp and the frequency f.
Source:
U. Tietze and C. Schenk, Halbleiter-Schaltungstechnik (German), 11th edition, Springer 1999, Chapter 14.5.2