The access-method-support vector list is pointed to by the ACB's
ACBAMSVL field in the ACB DSECT. This list describes the global variables
for the VTAM® program that processed
the OPEN macroinstruction.
The access-method-support vector list consists of the
following vectors:
- Component-Identification Vector: This vector contains product identification information about a major
component or feature of the VTAM licensed
program. This information is used by IBM® for VTAM program maintenance. When
a vector list contains multiple component-identification vectors,
the first vector designates the base VTAM product;
subsequent vectors designate features or other major components of VTAM. The vector ID is X'04'.
- Function-List Vector: This vector contains a variable-length bit string in which each bit corresponds
to a particular VTAM function.
If a bit is on, the corresponding function is present in the particular
release of VTAM. If a bit is
off, the function is not available. If the vector is not present,
or if it is shorter than expected, you can assume the value of the
missing bits to be 0. Refer to z/OS Communications Server: SNA Programmer's
LU 6.2 Reference for more information about the fields contained
in this vector. The vector ID is X'05'.
The information
contained in the function-list vector is also available at assembly
time in global variables created with the ISTGLBAL macroinstruction. z/OS Communications Server: SNA Programming describes the use of global variables.
- LU 6.2-Support-Function-List Vector: This vector is provided to indicate
which LU 6.2 options are supported by this release of VTAM. This vector is not present for applications
that do not use VTAM's APPC API. The vector ID is X'06'.
Each subvector in this vector list can have one of the following
values that corresponds one-to-one with LU 6.2 global variables:
- X'00'
- Option is not supported.
- X'01'
- Option is supported.
- X'02'
- Pass-through. (VTAM offers
support for the function, but the application program must implement
the function.)
Refer to z/OS Communications Server: SNA Programmer's
LU 6.2 Reference for more information about the fields contained
in this vector.
The vector list information is not available
until execution time. Refer to z/OS Communications Server: SNA Programmer's
LU 6.2 Reference for the list of global variables.
- Release-Level Vector: This vector contains the access method version and release number. The vector ID
is X'01'.