For instructions on how to read the PXX dump, refer to the CA Datacom® Core - 15.1 "Using Dumps in Problem Determination" section on "Reading the RWTSA Control Block"
"... The RWTSA (Read/Write Task Storage Area) portion of the PXX dump contains information on the individual user tasks. The request area is found at hex 100 into each RWTSA listing.
The task that causes the return code is identified by TASK-nnn, where nnn is the task ID, in the REASON-ERROR line on the PXX dump. The task can be located by scanning the dump for DBRWnnnn, where nnnn is the task number. ..."
The layout of the RWTSA is provided.