SUBPOOL macro

The SUBPOOL macro statement, when used in a VTAM® macro set, is a delimiter between groups of NAME macro statements to create LU 6.1 LTERM subpools.

At least one NAME macro statement must be defined within the VTAMPOOL; however, it is valid to define one or more subpools with no NAME statements. This definition creates a reserved subpool to which no terminals are allocated until reassigned there with the /ASSIGN command.

The subpools must be named to be used in IMS commands or session initiation requests. The LU 6.1 subpool names, specified on the required NAME keyword operand of the SUBPOOL macro statement, must follow standard z/OS® naming conventions and must be unique with respect to other LTERM subpool names within the VTAMPOOL. The subpool names must be unique among themselves, but need not be unique to other names used in an IMS system, such as LTERM names and transaction names. These subpools can only be used with statically defined ISC terminals. They cannot be used with ETO terminals.

If parallel sessions are defined in your system, at least one subpool must be defined.
Recommendation: Define at least one subpool for each parallel session defined in your system. Additional subpools can be defined if you desire.
For a session to be brought up, a subpool must be allocated to it. Thus, if you have defined two parallel sessions in your system and only one subpool, only one session can be brought up at any one time.

Dynamic definition

You cannot dynamically define LU 6.1 LTERM subpools.

Supported environments

The SUBPOOL macro can be used in the DB/DC and DCCTL environments.

Syntax

Read syntax diagramSkip visual syntax diagramSUBPOOLMSGDEL=SYSINFONONIOPCB,NAME= subpool name

Positional parameters

The SUBPOOL macro does not include positional parameters.

Keyword parameters

To find which parameters apply to your IMS configuration, refer to Selecting the appropriate macros to define your system.
MSGDEL=
Used for VTAM LU 6.1 devices and specifies which message types IMS should discard for this terminal. The default is SYSINFO.
SYSINFO│ NONIOPCB

SYSINFO, the default, specifies that IMS should discard DFS059 TERMINAL status messages for this terminal and also DFS3650 for SLU P devices.

NONIOPCB specifies that IMS should discard the following message types destined for this terminal:
  • Message switches
  • Messages inserted by an application program to an alternate PCB
  • /BROADCAST messages
  • DFS059 TERMINAL status messages
NAME=subpoolname
Used for VTAM LU 6.1 devices and names the LU 6 subpool.