DCB Parameters

Use the DCB parameters to specify DCB information for files that are created or replaced locally or remotely.
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Use the DCB parameters to specify DCB information for files that are created or replaced locally or remotely.
Users enter the DCB information when creating a file on the local system. Under these circumstances, the DCB information for the file that is transmitted is the default DCB information. Specifying the RECFM, LRECL, and BLKSIZE parameters overrides the default DCB information. The DCB information (specifically the LRECL operand) determines the maximum record length that the PC reads when receiving a binary file from z/OS. The local system confirms the accuracy of the three parameters.
When a z/OS-initiated receive is performed to a non-z/OS partner, it is recommended that all DCB-related parameters be coded in the SYSIN01 stream.
BLKSIZE
This parameter defines the block size of the file.
  • 0 to 99999
    Specifies a value 0 through 99999, indicating the block size of the file.
If a receive request originates from a non  z/OS partner, the BLKSIZE must be coded explicitly. The value of the parameter must be based on a reasonable estimate.
BLKSIZE=0 is valid only if the value of RECFM is FB, FB
x
, VB, or VB
x
. When BLKSIZE=0, z/OS (not CA XCOM Data Transport) determines the block size.
Default:
If a send or receive request of any type originates from a z/OS partner, BLKSIZE of the z/OS data set.
LRECL
This parameter defines the logical record length of the file.
  • 0 to 99999
    Specifies a value 0 through 99999, indicating the logical record length of the file.
If a receive request originates from a non-z/OS partner, the LRECL is coded explicitly. The value of the parameter must be based on a reasonable estimate.
For receive requests where the target character set is different from the source character set. The LRECL has a value that is specified which allows the difference in the number of bytes per character. If the LRECL is not large enough to support the target character set, an XCOMM0144E SENDING RECLEN > MAX TARGET LENGTH error is issued.
Default:
LRECL of the z/OS data set. If a send or receive of any type request, originates from a z/OS partner.
RECFM
This parameter specifies the z/OS record format that is associated with a data set. This parameter uses the same format as the z/OS JCL RECFM parameter.
  • F
    Fixed
  • FA
    Fixed ASA
  • FB
    Fixed Blocked
  • FBA
    Fixed Blocked ASA
  • FBM
    Fixed Blocked Machine
  • FBS
    Fixed Blocked Standard
  • V
    Variable
  • VA
    Variable ASA
  • VB
    Variable Blocked
  • VBA
    Variable Blocked ASA
  • VBM
    Variable Blocked Machine
  • VBS
    Variable Blocked Spanned
  • VS
    Variable Spanned
  • U
    Undefined
RELEASE
This parameter specifies whether the remote partner is to release unused DASD space when creating a file.
  • YES
    The remote partner is to release unused DASD space.
    The unused DASD space that is specified for the transfer is released when the file is closed at the end of the transfer.
  • NO
    The remote partner is not to release unused DASD space.
Default:
No
Examples of DCB Information
The following are examples of DCB information that you can code in your SYSIN01 data set, depending on the type of files being created:
Example 1
RECFM=FB
LRECL=80
BLKSIZE=8000
Example 2
RECFM=VB
LRECL=516
BLKSIZE=23440
Example 3
RECFM=U
BLKSIZE=19069