A set of diagnostic systems essential for core ignition burn control in future tokamak fusion reactors, including ITER, has been developed.This diagnostic set is based on examination of various feedback controlalgorithms in the ignition access, steady state and shutdown phases of ignition burn in the plasma core. The control algorithms used here are based ona combination of H mode power threshold and fusion power. The external heating power is determined either by the H mode power threshold or the fusion power, and the fuelling rate by the fusion power. From over-ignition to subignition, these algorithms sufficiently control all the core burn condition, such as the sudden change in various plasma parameters, as demonstrated numerically. A feedback control diagram is presented for achieving burn control consisting of, for example, measurements of line averaged density, net alpha heating power, bremsstrahlung lossand the synchrotron radiation loss.