The SELFCAL behaviour can be adjusted through control variables named SELF_... (see EXA SELF_ for a list), in addition to the control variables of UV_MAP (MAP_...) and CLEAN (CLEAN_...)
The most important variable is SELF_TIMES, a variable length array which controls the integration time at each loop. SELF_NITER and SELF_MINFLUX also control the number of Clean components and minimum flux retained in each loop. The size of these arrays define the number of loops.
See HELP SELFCAL SELF_LOOP to find out how to control the number of loops.