Defining sequential (BSAM) devices

You can use a pair of input and output sequential data sets to simulate a terminal to CICS®. For example, you might do this to test an application program before the intended terminal becomes available.

To do so, code the following DFHTCT TYPE= macros:

    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.

You must code a DD statement for each sequential data set defined by an SDSCI macro. The DD name on the DD statement must be the same as the name coded on the DDNAME parameter (or, by default, on the DSCNAME parameter) of the SDSCI macro. For example, you could use the following DD statements for sequential input and output:

//CARDIN  DD  *,DCB=BLKSIZE=80
       .
    Statements containing valid transactions
       .
/*
//PRINTER DD  SYSOUT=A,DCB=BLKSIZE=132

This example of an I/O combination simulates a terminal to a CICS application program. There is an example of the SDSCI statements supporting this CARDIN/PRINTER combination in the copybook DFH$TCTS, which is defined in the sample TCT, DFHTCT5$. DFH$TCTS is supplied in CICSTS54.CICS.SDFHSAMP. Input to the application program is submitted through the input stream (CARDIN), and output to the terminal is sent to the output stream (PRINTER). If the BLKSIZE parameter is defined in the TCT for the data set, you can omit it from the JCL. However, if it is not defined in the TCT, the block size defaults to 0, and if you also omit it from the DD statement for the data set, you get message IEC141I 013-34. There are other examples of DD statements for I/O sequential data sets in some of the CICS-supplied installation verification procedures. You can find them in CICSTS54.CICS.SDFHINST after installation.

You can also use two DASD data sets to simulate a terminal. You must code a DD statement for each data set defined by an SDSCI macro, and the DD name on the DD statement must be the name coded on the DDNAME (or DSCNAME) parameter of the SDSCI macro.

For example, you might code:

//DISKIN1  DD DSN=SIMULATD.TERMINAL.IN,
//         UNIT=3380,DISP=OLD,VOL=SER=volid
//DISKOT1  DD DSN=SIMULATD.TERMINAL.OUT,
//         UNIT=3380,DISP=OLD,VOL=SER=volid

Input from this simulated terminal is read from the DISKIN1 data set. Output to the terminal is written to the DISKOT1 data set.

Each statement in the input file (from CARDIN or DISKIN1 in the examples used earlier), must end with a character representing X'E0'. The standard EBCDIC symbol for this end-of-data hexadecimal value is a backslash (\) character, and this is the character defined to CICS in the pregenerated system. You can redefine this for your installation on the EODI system initialization parameter; see Specifying CICS system initialization parameters for details.