Normally, a caller (such as CICSPlex® SM) invokes the MVS router and passes it request type, requester, and subsystem parameters via the RACROUTE exit parameter list. Using these parameters, the MVS router calls the router exit which, on completing its processing, passes a return code to the router. If the return code is '0', as defined above, the router invokes RACF. RACF reports the result of that invocation to the router by entering return and reason codes in register 15 and register 0 respectively. The router converts the RACF return and reason codes to router return and reason codes and passes them to the caller. The router provides additional information to the caller by placing the unconverted RACF return and reason codes in the first and second words of the router input parameter list.
If your installation does not use RACF, you can make the MVS router exit pass control to an alternative ESM. However, if you do so you must still provide CICSPlex SM with the RACF return and reason codes that it expects to receive. You set the router exit return code, as defined in Table 1, so that RACF is not invoked; and you simulate the results of a RACF invocation by coding the exit so that it places the RACF return and reason codes in the first and second fullwords of the router input parameter list. RACF return and reason codes are documented in the MVS/ESA Authorized Assembler Programming Reference manual.