$B PUN(nn) and $B R(nnnnn).PU(m)

Function

To backspace punch output a specified number of cards, to the beginning of a data set, or to the most recent checkpoint.

Syntax


>>-$B--+-PUNnn------+--+------+--+--------------------+--------->
       '-Rnnnnn.PUm-'  '-,--D-'  '-,--C--+----------+-'   
                                         '-,--nnnnn-'     

>--+----------+------------------------------------------------><
   '-,--nnnnn-'

Parameters

nn: The identifier of the local punch (1-99) on which JES2 backspaces output.
nnnn: The output is backspaced nnnn (1-9999) cards.
nnnnn: The identifier of the remote workstation R (1-32767) that is attached to punch m (1-7).
m: The identifier of the punch (1-7) that is attached to the remote workstation Rnnnnn (1-32767).
C: The output is backspaced to the most recent checkpoint. JES2 assumes that all data up to the most recent checkpoint has punched successfully. Backspacing to the most recent checkpoint is the only way JES2 can ensure no loss of data for remote punches.
You can also specify nnnn with C, which causes JES2 to backspace the output nnnn cards further than the most recent checkpoint.
D: The output is backspaced to the beginning of the data set. Punching resumes at the beginning of the data set.

Authority Required

This command requires device authority. The description of the $T RDRnn command explains how to ensure that the authority of the appropriate MVS™ system command group is assigned.

This command requires update security access authority. For a description of assigning command input authority, see z/OS JES2 Initialization and Tuning Guide, SA32-0991.

Processing Considerations

If you omit D, C, and nnnn, one card is the default backspace.
The amount of output between checkpoints is controlled by either:
- The CKPTLNS and CKPTPGS parameters on the /*OUTPUT JES2 statement.
- The CKPTLINE and CKPTPAGE parameters on the PRTnn and Rnn.PRm initialization statements, the OUTPUT JCL statement, or using the $T device command.
The $B command is useful if a punch jam causes a loss of punched cards. After you clear the jam, you can backspace to a point in the data set before the punch jam and resume punching.

Scope

Single member. The values supplied for this command will be in effect for this member only. There is no need to have this command issued to all members of the MAS.

Messages

The $HASP170 message displays the status of output processing on the specified punch.

Examples

 1   $b r9.pu1,c

  $HASP170 R9.PU1 BACKSPACED

JES2 backspaces the output on punch 1 of remote 9 to the most recent checkpoint. If no checkpoint exists, or if the card currently being punched precedes the most recent checkpoint (this can happen if the punch was previously repositioned behind the most recent checkpoint by another $B command), JES2 backspaces the output to the beginning of the data set. For example, if the most recent checkpoint was taken at card 250 and card 245 is currently being punched, JES2 will backspace the output to the beginning of the data set.

 2   $b r11.pu1,c,10

  $HASP170 R11.PU1 BACKSPACED

JES2 backspaces the output on punch 1 of remote 11 ten cards behind the most recent checkpoint. If there is no checkpoint, or if the card currently being punched precedes the most recent checkpoint, JES2 backspaces the output to the beginning of the data set.