Modifying the EID by exits XPCREQ, XPCERES, and XPCREQC

It is not possible to modify the EID to make major changes to requests. It is not possible, for example, to change a LINK request to a different type of Program Control request. However, you can make minor changes to requests, such as to turn on the existence bit for SYSID so that the request can be changed into one that is shipped to a remote system.

The list that follows shows the bits in the EID that can be modified. Any attempt to modify any other part of the EID is ignored.

PC_BITS1

X'40'

The existence bit for the COMMAREA

X'20'

The existence bit for LENGTH

X'10'

The existence bit for INPUTMSG

X'08'

The existence bit for INPUTMSGLEN

X'04'

The existence bit for DATALENGTH

X'02'

The existence bit for SYSID

X'01'

The existence bit for TRANSID.

PC_BITS2

X'40'

The existence bit for CHANNEL.

PC_EIDOPT5

Not used for a PC link request.

Bits in the EID should be modified in place. You should not modify the pointer to the EID. (Any attempt to do so is ignored by CICS®.)

The EID is reset to its original value before return to the application program. That is, changes made to the EID are retained for the duration of the program control request only.

Your user exit program is prevented from making major changes to the EID.