You can use the exchange request of the IEFSSVT macro to associate the function routine with a supported function code so that the new function routine gets control for that function.

Inputs

Before invoking the IEFSSVT macro, the subsystem must use the IEFSSVTI macro to create a table that relates function routines and the function codes they support.

If possible, the SSI reclaims the space in the subsystem vector table occupied by the function routines associated with the disabled function codes. If a function routine does not support any remaining function codes, the SSI makes its subsystem vector table space available for reuse in subsequent enable requests.