Bin System (CMS TMCs Only) › Implementing a Bin System › Step 4 - Reviewing the User Exits › BINEXIT3

BINEXIT3

USREXIT3 validates the tape label. It performs a series of comparisons and issues a return code to CA VM:Tape based on the results. BINEXIT3 provides processing for the Bin system in addition to the functions furnished by USREXIT3.

BINEXIT3 checks the volser to determine whether the volume is a member of the Bin system. Unless you modified the bin tape identifier in the VMTBIN macro, CA VM:Tape assumes that all volsers with the first two characters BN are bin volumes. If the volume is not part of the Bin system, a return code of zero (0) is issued.

Note: For more information, see USREXIT3 User Exit.

• If the volume is part of the Bin system, BINEXIT3 tests the scratch bit in the TMC:
• If this is a scratch volume (during the entry process), BINEXIT3 checks whether the tape has been mounted read/write or read-only:
  • If the tape is mounted read/write, BINEXIT3 rejects the mount with an error message.
  • If the tape is mounted read-only, BINEXIT3 checks the VOL1 record:
• If a VOL1 record is not on the tape (that is, the tape is NL), the key string "- - NL - -" is stored as the internal volser by the BINACNT user exit. It issues a return code of zero (0). This return code indicates that normal CA VM:Tape validation should be performed.
• If a VOL1 record is on the tape, the serial number from the record is saved and passed by the user exit communication work area to the BINACNT user exit. BINACNT stores the serial number in the INTVS field as the tape’s internal volser. It issues a return code of 4, indicating that CA VM:Tape should accept the tape without performing normal VOL1 validation.
  • If this is not a scratch volume (for regular mounts after entry), BINEXIT3 tries to validate the volser:
  • If there is no VOL1 record, the key string "- - NL - -" is stored as the internal volser, and return is made to CA VM:Tape with a return code of zero (0). This indicates that normal CA VM:Tape validation should be performed.
  • If there is a VOL1 record, the value in the INTVS field in the accounting area is compared to the volser in the VOL1 record:
• If the volsers match, BINEXIT3 issues a return code of 4. This return code indicates that CA VM:Tape should accept the tape without performing normal VOL1 validation.
• If the volsers do not match, BINEXIT3 issues a return code of 8. This return code indicates that CA VM:Tape should unload the tape and request the correct volume.