A light ion minority heating scheme based on long wavelength fast magnetosonic wave (FMSW) global resonance excitation appears to be promising for open traps. This scheme has been studied numerically using the 2D code PLFEM. This code uses both local and nonlocal approximations and can search for global resonances. The global FMSW resonance width (TE_1,0,2 mode), which is caused by hydrogen minority cyclotron energy absorption, is found to be a maximum for a minority concentration of C_H=1-2%. For these concentration values a substantial discrepancy between the local and nonlocal approximations occurs. This discrepancy is a result of local Alfven resonance excitation in the vicinity of the hydrogen cyclotron zone in a cold plasma. The Alfven resonance disappears when even a slight thermal motion of the ions (nonlocality) is taken into account. By proceeding with global resonance field patterns a suitable antenna system consisting of two loops fed with opposite phases has been chosen. Calculations have demonstrated that the antenna system has good electrotechnical qualities