Sequential devices

CICS® uses BSAM to control sequential terminals such as card readers, line printers, magnetic tape units and DASD. Sequential terminals provide simulation of actual terminals, and can be used before the actual terminals become available. Sequential terminals can also be used during the testing of new applications.

To define a sequential device, code the following macro instructions:

       DFHTCT TYPE=INITIAL,
              ACCMETH=(NONVTAM)    defining the access
                                   method

(Define the following macro instructions contiguously.)

  DFHTCT TYPE=SDSCI,
         DSCNAME=isadscn,     defining the input
         DDNAME=indd, ...      data set
  DFHTCT TYPE=SDSCI,
         DSCNAME=osadscn,     defining the output
         DDNAME=outdd, ...     data set
  DFHTCT TYPE=LINE,
         ISADSCN=isadscn,
         OSADSCN=osadscn, ...
  DFHTCT TYPE=TERMINAL,
         TRMIDNT=name, ...

The two data sets defined by the DFHTCT TYPE=SDSCI macros simulate a CICS terminal known by the name specified in the TRMIDNT operand of the DFHTCT TYPE=TERMINAL macro. The DSCNAMEs of the input and output data sets must be specified in the ISADSCN and OSADSCN operands of the DFHTCT TYPE=LINE macro respectively.

The end of data indicator (EODI) for sequential devices can be altered using the EODI system initialization parameter.