open_valve()
set_pol_cplus(offset = None)
set_file('Mn_hyst_plus')
hyst_cont(field_x, -6.8, 6.8, 2.0, [638.6, 637.0])


set_pol_cminus(offset = None)
set_file('Mn_hyst_minus')
hyst_cont(field_x, 6.8, -6.8, 2.0, [638.6, 637.0])
close_valve()