Types of virtual, reconfigurable connection
The following virtual (reconfigurable) connections exist in a configuration:
between the channels and the devices generated directly on them
between the channels and the controllers generated on them
between the controllers and the devices generated on them
A distinction is made between inner and outer virtual connections:
An inner connection always goes to an inner unit (e.g. from DVC to CTL or from CTL to CHN).
An outer connection goes to an outer unit (CHN to CTL or CTL to DVC).
States of virtual, reconfigurable connections
INCLUDED
The virtual connection to the system has been established and can be used for input/output. This state is set:
after the system startup, unless one of the conditions for the REMOVED state is fulfilled (see below)
after successful invocation of the INCLUDE-DEVICE-CONNECTION (INC) command
REMOVED
The virtual connection to the system has been cleared and cannot be used for input/output. The REMOVED state is further subdivided into:
REMOVED EXPLICITLY
This state is set:after system initialization if the relevant unit was modified in the startup parameter service with the IOCONF statement MOD-IO-UNIT *CON(..., STATE=REM)
after automatic reconfiguration by the operating system
after successful invocation of the REMOVE-DEVICE-CONNECTION command.
REMOVED IMPLICITLY
This state is set if the inner hardware unit is in the DETACHED state.
REMOVE-PENDING
The virtual connection is still in use and thereafter is no longer available to the system. This state occurs only during a wait time in the REMOVE-DEVICE-CONNECTION or DETACH-DEVICE command. If the reconfiguration job can be carried out, the connection is placed in the REMOVED state; otherwise the INCLUDED state is set (reinstated). The REMOVE PENDING state is subdivided into:
REMOVE-PENDING EXPLICITLY
This state is set if the connection is cleared directly [with wait time (operand FORCE=NO... in the REMOVE-DEVICE-CONNECTION command)].REMOVE-PENDING IMPLICITLY
This state is set if the inner unit of this connection is in the DETACH-PENDING state.