We can pass data thru Accept to called program(subprogram).
Need to write Accept statement in called program.
This is like file handling in called program. File will be processed and the output will be passed to calling program. After completion of called program we need to restore output values, no need of input values, in such case we can pass Input from JCL using FILE or Sysin.
Anyway we will not write any step to execute called program in our JOB, calling program will be added to step.