VTAM macroinstruction language

VTAM® macroinstructions are assembler macroinstructions and follow the same rules. (Refer to z/OS Communications Server: SNA Programmer's LU 6.2 Reference for details on coding rules for these macroinstructions.) With only a few exceptions, the operands on VTAM and VTAM APPCCMD macroinstructions can be entered in any order.

The four categories of VTAM macroinstructions are:

Declarative: These macroinstructions build control blocks during assembly.
RPL-Based: These macroinstructions use the RPL to describe requests to VTAM. Most of the macroinstructions this manual discusses are RPL-based, including APPCCMD.
ACB-Based: These macroinstructions tell VTAM that the application program is beginning or ending its use of VTAM services. They are required for VTAM to recognize the application program as active.
Manipulative: These macroinstructions build and manipulate control block values during application program execution. They do not support the LU 6.2-unique control block fields, but they do support some control block fields that are common to both LU 6.2 and other application programs.