IBM OS/390 User Manual

// PAUSE

mount tape 123456 on an available drive.

// ASSGN SYS005,CUU

- or -

// ASSGN SYS005,Drive

The operator gets an error message and enters the correct tape assignment,
such as:

// ASSGN SYS005,481

Another example is TLBL without VOLSER or a known invalid VOLSER.

// TLBL 999999

Forcing error conditions in VSE JCL that require operator intervention becomes a
simple tape management method.

IGNORE, DELETE and NEWTAP are replies that the operator can use to answer
the messages.

IGNORE can be used when the data set name in the JCL does not
match the data set name on the tape. IGNORE says go ahead and
read it anyway. It acts as a BLP (Bypass Label Processing) in
OS/390. This allows tapes with any labels or no labels to be
processed without label verification.

Another approach is to leave the data set name blank which allows
whatever is on the drive to be read.

DELETE is used to create a new file disk when files already exist in
these extents. Using DELETE will overlay the previous extents.
DELETE can also be used to overwrite extents when someone has
used your extent.

NEWTAP is used to unload the volume currently mounted on the
drive and allow the operator to mount another volume.

Comment lines can be inserted in the VSE JCL, wherever a valid JCL is allowed.
Comment lines that start with an asterisk are displayed on the console and, if
option LOG is set, the message is also written to SYSLST.

To have comments in the VSE JCL not written to the console use 

′/

*

′ 

instead of

′

*

′.

Exercise caution as to where they are placed because 

′/

*

′ 

still means end of

data. Some people also accomplish this by using 

′/.′. 

What is important is that

the first word must be a valid JCL label.

The MVS JCL offers no possibility to have the comments written to the console;
comment lines are only written to the job

′

s output.

The PAUSE statement provides the ability to halt job execution and wait for
operator intervention. VSE comment lines (with an asterisk in position 1) can be
used before a PAUSE statement to display multi-line messages to the operator.
See 4.5.1, “Sample VSE JCL” on page 92 where there is an example of a
multiple line message being sent to the console with a comment line and a
PAUSE to send a message to the operator and wait.

Chapter 4. Job Control Language (JCL) Differences and Considerations