An IMS DFS2389I XCF SEND RC=0000000C Reason=00000004 is triggered when a TPX modify command is attempted.

Products

• TPX - Session Management

Issue/Introduction

After a TPX modify command, such as  F TPX,D VT,ALL, the IMS control region generates several messages, displayed below.
  DFS2389I XCF SEND RC=0000000C Reason=00000004.

Why does a TPX display console command generate an XCF buffer overflow condition in IMS ?

Environment

Release : 5.4
Component : Z/OS

Resolution

TPX does not interface with IMS for any TPX internal function and behaves only as session manager for 3270 sessions for application like CICS, IMS, etc.

The modify command for, "F TPX,D VT,ALL" , is a TPX command, not a VTAM or XCF command.

TPX is only issuing WTOs to display the response to the TPX Display Virtual Terminal command.
TPX is not interfacing with XCF or IMS related to TPX OPER command in question.

TPX issues WTOs to display in multiple column response from searching its own internal control blocks.
TPX does not interface with VTAM for this information.

TPX uses XCF when it is in a Generic Resource Configuration but does not intercept other XCF messages.
If TPX is not running as a Generic resource, this does not apply.

With respect to the IMS message, DFS2389I XCF SEND RC=0000000C Reason=00000004,
The above documented DFS message is an external vendor issue (IBM IMS-OTMA),  and not related to TPX.