When the Attunity CICS Adapter is configured to run a CICS program that calls DB2, make sure to setup the following:
1. Verify that the program is defined in the RCT with AUTHTYPE=USERID and not AUTHTYPE=TERMID/OPID
2. Make sure that the Attunity user on the Mainframe is able to access DB2
3. Create a DB2TRAN entry for the transaction EXCI that the connection runs under.

Failing to do so could cause to the below error at runtime:

[J0036] = client.requestError (cics.onExecute): CICS_EXECUTE Failed:
CICS function CICS_DPLRequest return with USER_ERROR(12)
exci_reason is 422 sub_reason1 is 0 sub_reason2 is 0
DPL Info: dpl_resp 0 dpl_resp2 0 dpl_abcode ADPL

A good reading can be found at:
“DB2 Guide” IBM Library Server: How CICS connects to DB2