Issuing the CHECK Macro

Before issuing the CLOSE macro, a CHECK macro must be issued for all DECBs that have outstanding I/O from WRITE macros. When CLOSE TYPE=T is specified, a CHECK macro must be issued for all DECBs that have outstanding I/O from either WRITE or READ macros except when issued from EODAD.

In Figure 1 the data sets associated with three DCBs are to be closed simultaneously. Because no volume positioning parameters (LEAVE, REWIND) are specified, the positioning indicated by the DD statement DISP parameter is used.
Figure 1. Closing Three Data Sets at the Same Time
   CLOSE      (TEXTDCB,,CONVDCB,,PRINTDCB)