Coding the JCL EXEC statement for generating an IOCDS

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In the EXEC statement, code the name of the IOCP program in the PGM parameter and the following PARM options to generate an IOCDS. (The examples later in this chapter describe the JOB and DD statements for an IOCP job.)
Note: PARM parameter defaults allow you to generate an IOCDS and to produce reports. However, the defaults do not allow you to write an IOCDS to the Support Element hard disk.

IOCP processes all input statements and parameters. IOCP flags as errors any non-IOCP input and also indicates errors found in IOCP statements and parameters. IOCP prints all input, including all comment cards (all cards with an asterisk (*) in column 1 or .* in columns 1 and 2). 

PARM='WRTCDS=Ax|NO,LINECOUNT=n|55,CHECKCPC=YES|NO'
WRTCDS=
specifies whether or not IOCP writes an IOCDS to the support Element hard disk. All of the WRTCDS options except NO cause IOCP to write an IOCDS. You can write an IOCDS only from an authorized logical partition (that is, I/O Configuration Control Authority is enabled).
IOCP writes the IOCDS only if:
  • No errors are encountered during IOCP processing
  • The z/OS system operator grants permission in response to message ICP050D or the user attempting to write the IOCDS is authorized by an installed security product (for example, RACF)
  • The IOCDS is not write protected.
Request IOCP to write the IOCDS only after you have done the following:
  • Checked the syntax of the input statements
  • Generated an IOCDS based on the configuration defined in the statements
  • Reviewed reports on the generated IOCDS
  • Checked to see whether or not the generated IOCDS is correct.

To replace a write protected IOCDS, you must first remove write protection. Click Disable Write Protection n under Options on the Input/Output Configuration window of the Support Element to remove write protection.

HCD and write protection: You can use HCD to set and remove IOCDS write protection. For more information, see z/OS Hardware Configuration Definition User's Guide, SC34-2669.

When IOCP writes an IOCDS to the Support Element hard disk, it overwrites the previous configuration data in that IOCDS, even if that IOCDS is the active IOCDS. (The active IOCDS is the one used for the last power-on reset or the last dynamic activation from the system control program (SCP).)

The valid options for WRTCDS are Ax and NO.
Ax
specifies that IOCP should write the Ax IOCDS (where x is 0, 1, 2, or 3) to the Support Element hard disk.
NO
specifies that IOCP should not write the IOCDS to the Support Element hard disk.

NO is the default if you do not code WRTCDS.

Code or use the default WRTCDS=NO when you test the input file and do not want to write to the Support Element hard disk until you have successfully tested and checked the input file.

Also, you must code or use the default WRTCDS=NO when you run IOCP on a CPC that does not require ICPIOCP. However, certain CPCs allow an IOCDS to be written in anticipation of supporting ICPIOCP.

LINECOUNT=
n
specifies the number of lines that IOCP is to print on a page of the IOCP output listing and configuration reports, including the heading of the report. Code a decimal value in the range of 20-99.
55
is the default number of lines (including the heading) that IOCP prints on a page of the IOCP output listing and configuration reports.
CHECKCPC=
YES
specifies that IOCP generates an IOCDS as follows:
  • Based on the CPC on which IOCP is running if writing an IOCDS. IOCP ignores the SYSTEM= keyword on the ID statement if specified.
  • Based on the CPC on which IOCP is running if not writing an IOCDS and the SYSTEM= keyword was not specified.
  • Based on the SYSTEM= parameter if specified and IOCP is not writing an IOCDS.

YES is the default.

NO
specifies that IOCP writes the IOCDS in preparation of a CPC upgrade. IOCP generates an IOCDS based on the SYSTEM= parameter on the ID statement and writes the IOCDS to the current CPC. See Machine rules to determine which SYSTEM= parameters are valid with CHECKCPC=NO and which CPCs can have ICPIOCP write an IOCDS to them.

The IOCDS cannot be used to power-on reset the current CPC until it is upgraded to the type of CPC that the IOCDS supports. For example, if IOCP generates an IOCDS for an 8561 CPC using SYSTEM=(8561,1) and writes the IOCDS to a general purpose 3906 model, the IOCDS cannot be used for power-on reset until the 3906 is upgraded to an 8561 model CPC.

A WRTCDS option other than NO is required. Also, the SYSTEM keyword on the ID statement must be specified.

Attention: Use CHECKCPC=NO only in preparation of a CPC upgrade. After the upgrade, IBM recommends that you write an IOCDS using CHECKCPC=YES at your earliest convenience. This prevents the possibility of using the initial IOCDS for a second upgrade to a CPC, which will not support the IOCDS and will fail power-on reset.