EXTRACT ATTACH (MRO)

Description

EXTRACT ATTACH retrieves a set of values that are held in an attach header control block, or that have been built previously. For the command to retrieve information from a received attach Function Management Header (FMH), EIBATT must have been set during a RECEIVE or CONVERSE command.

For more information about MRO and IRC, see Introduction to CICS intercommunication .

Options

ATTACHID(name)

specifies that values are to be retrieved from an attach header control block. The name (1–8 characters) identifies this control block to the local task.

CONVID(name)

identifies the conversation to which the command relates. The 4-character name identifies either the token returned by a previously executed ALLOCATE command in EIBRSRCE in the EIB, or the token representing the principal session (returned by a previously executed ASSIGN command).

DATASTR(data-area)

corresponds to the data stream profile field, ATTDSP, in an LUTYPE6.1 attach FMH.

For communication between two CICS® systems, no particular significance is given by CICS to the data stream profile field in an attach FMH. For most CICS applications, the option can be omitted.

The value returned in the data area is a halfword binary value. Only the low-order byte is used; the SNA-defined meanings of the bits are as follows:

0-7    reserved - must be set to zero
8-11   0000 - user-defined
       1111 - SCS data stream
       1110 - 3270 data stream
       1101 - structured field
       1100 - logical record management
12-15  defined by the user if bits 8-11
       are set to 0000; otherwise reserved
       (must be set to zero)

IUTYPE(data-area)

corresponds to the interchange unit field, ATTIU, in an LUTYPE6.1 attach FMH.

For communication between two CICS systems, no particular significance is attached by CICS to the interchange unit field in an attach FMH. For most CICS applications the option can be omitted. The value returned in the data area is a halfword binary value. Only the low-order 7 bits are used; the SNA-defined meanings of the bits are as follows:

0-10   reserved - must be set to zero
11     0 - not end of multichain interchange unit
       1 - end of multichain interchange unit
12,13  reserved - must be set to zero
14,15  00 - multichain interchange unit
       01 - single chain interchange unit
       10 - reserved
       11 - reserved

PROCESS(data-area)

corresponds to the process name, ATTDPN, in an LUTYPE6.1 attach FMH.

For communication between two CICS systems, a transaction running in one system can acquire a session to the second system and can identify the transaction to be attached; in the second system the identification is carried in the first chain of data sent across the session.

In general, the first four bytes of data identify the transaction to be attached. However an attach FMH, identifying the transaction to be attached, can be built and sent. The receiving CICS system uses just the first four bytes of the process name as a transaction name. No significance is attached by CICS to process names in attach FMHs sent in chains of data other than the first.

For communication between a CICS system and another subsystem, refer to documentation supplied by the subsystem about how to use the process name field in an attach FMH.

QUEUE(data-area)

corresponds to the queue name, ATTDQN, in an attach FMH. For communication between two CICS systems, no significance is attached by CICS to the queue name in an attach FMH.

For communication between a CICS system and another subsystem, refer to documentation supplied by the subsystem about how to use the queue name field in an attach FMH.

RECFM(data-area)

corresponds to the deblocking algorithm field, ATTDBA, in an LUTYPE6.1 attach FMH.

For communication between two CICS systems, no particular significance is attached by CICS to the deblocking algorithm field in an attach FMH. For most CICS applications, the option can be omitted.

For communication between a CICS system and another subsystem, refer to documentation supplied by the subsystem about how to use the interchange unit field in an attach FMH.

The value returned in the data area is a halfword binary value. Only the low-order byte is used; the SNA-defined meanings of the bits are as follows:

0-7   reserved - must be set to zero
8-15  X'00' - reserved
      X'01' - variable-length
              variable-blocked
      X'02' - reserved
      X'03' - reserved
      X'04' - chain of RUs
      X'05'through X'FF' - reserved

RESOURCE(data-area)

corresponds to the resource name, ATTPRN, in an LUTYPE6.1 attach FMH.

For communication between two CICS systems, no significance is attached by CICS to the resource name in an attach FMH.

For communication between a CICS system and another subsystem, refer to documentation supplied by the subsystem about how to use the resource name field in an attach FMH.

RPROCESS(data-area)

corresponds to the return process name, ATTRDPN, in an LUTYPE6.1 attach FMH.

For communication between two CICS systems, no significance is attached by CICS to the return process name in an attach FMH.

For communication between a CICS system and another subsystem, refer to documentation supplied by the subsystem about how to use the return process name field in an attach FMH.

RRESOURCE(data-area)

corresponds to the return resource name, ATTRPRN, in an LUTYPE6.1 attach FMH.

For communication between two CICS systems, no significance is attached by CICS to the return resource name in an attach FMH.

For communication between a CICS system and another subsystem, refer to documentation supplied by the subsystem about how to use the return resource name field in an attach FMH.

SESSION(name)

specifies the symbolic identifier (1–4 characters) of a session TCTTE. This option specifies the alternate facility to be used.

Conditions

62 CBIDERR

occurs if the requested attach header control block cannot be found.

Default action: terminate the task abnormally.

16 INVREQ

occurs if incorrect data is found.

Default action: terminate the task abnormally.

61 NOTALLOC

occurs if the facility specified in the command is not owned by the application.

Default action: terminate the task abnormally.