Scenario: Workstation allocation

This example illustrates how two workstations are allocated to two different subsystems.

In this scenario, subsystem A and subsystem B have workstations DSP01 and DSP02 in their subsystem descriptions (the workstation entries specify AT(*SIGNON)).

Assume that both workstations are varied on when subsystem A is started.

Subsystem A allocates both workstations and shows the sign-on display on both. Even though subsystem A has the sign-on display shown on the workstations, they can be allocated by another subsystem or job; the workstation is then no longer available to subsystem A.

When a user (USER1) signs on to workstation DSP01, the device is allocated to USER1's job, which is running in subsystem A. Workstation DSP02 is still at the sign-on display. Thus it can be allocated by another subsystem or job. It is then no longer available to subsystem A.

Subsystem B is started. Because USER1 has signed on to workstation DSP01, subsystem B cannot allocate the device. Subsystem B requests allocation of the device when it becomes available. DSP02 is allocated to subsystem B because no one has signed on to it in subsystem A. Any jobs started on DSP02 run in subsystem B.

USER1 signs off. Because the user job was running in subsystem A, that subsystem displays the sign-on display so that another user can sign on the workstation and run in subsystem A. If subsystem A is ended, workstation DSP01 is allocated by subsystem B (because it has an outstanding request to allocate the device.)

The name of the subsystem that currently has a workstation allocated appears in the upper right corner of the IBM-supplied sign-on display.