JES2 can issue ENF signal 40 during initialization or orderly termination to communicate the fact that JES2 has initialized, or is ending.

JES3 issues ENF signal 40 during initialization or when the JES3 address space is terminating (regardless of orderly shutdown or abnormal termination).

You might need to know when JES is initializing or ending when using SSI function code 54 to obtain relatively static (information that is not likely to change between restarts) information about a JES subsystem. If JES ends and is restarted with a new level, or with a different functional capability, you will need to reissue this SSI request to obtain information about the new capabilities of JES. During initialization or orderly termination, JES issues event notification facility (ENF) signal 40, for which authorized callers can listen. For information about how programs can listen for ENF signals, see the description of using the ENFREQ macro in z/OS MVS Programming: Authorized Assembler Services Guide. Note that the users of ENFREQ must be authorized.

• Fixed header input section

  The user provides this information before issuing IEFSSREQ. This information is explained Fixed Header Input Section.

• Fixed header output section

  Information returned by all called subsystems is returned in this section. This information is explained Fixed Header Output Section.

• Installation variable output section (JES)

  Installations can supply their own keywords, or override one or more keywords returned in the system variable output section. This information is explained Installation Variable Output Section.

• System variable output section

  The called subsystem returns subsystem-specific information in the form of keyword value specifications. This information is explained System Variable Output Section.