JES3, a z/OS® MVS™ subsystem, manages resources and work flow before and after jobs are processed. You can enable JES3 to allocate 3592 Model J tape drives and tape volumes in an SMS-managed IBM® tape library environment (automated or manual) for 3590 Model B emulation only. To do so, you need to specify at least one of these library device group (LDG) names in your JES3plex. An LDG is a predefined set of tape subsystems within a JES3plex.

• LDGdddd. dddd=359J indicates that a 3592 Model J tape drive emulates a 3590 Model B in any library within the JES3plex.
• LDJsssss. The serial number sssss indicates the library within which a 3592 Model J tape drive that emulates a 3590 Model B resides.

Related reading:

See z/OS JES3 Initialization and Tuning Reference for additional information on LDGs, JES3, and JES3plex.