What limitation does TPX have when setting up VT selection for a MRO CICS (TOR /AOR) environment. Observed sensecode 0824?

Products

• TPX - Session Management

Issue/Introduction

Logging on to a CICS(TOR) region and the transaction is executed in a CICS(AOR) region results in a sensecode 0824 and the transaction abends.
Can CICS TOR and AOR  use the same masking rule IF the VT type GRP is used?

Environment

Release: 5.4
Component: TPX for Z/OS

Cause

It was observed that the TPX virtual terminal type (GRP) used for the CICS(TOR) was already in session with the CICS(AOR) region.

Resolution

This problem is caused by using the same GROUP virtual terminal for both applications, CICS(TOR) and CICS)AOR) regions.
Terminal-owning region (TOR) and application-owning region (AOR) cannot use the same masking rule IF the VT type 'GROUP' is used.
TPX needs to be setup in a way that it does not select the same virtual terminal for CICS(TOR) and CICS(AOR) regions.

Define one (TOR / AOR)  with TYPE=UNQ and the other with TYPE=GRP in the ACT  - since a TPX UNQ and a GRP terminal is unique.
If TYPE=GRP virtual terminals are used for both CICS(TOR) and CICS(AOR) regions setup masking rules.

Assume 300 group VTs are defined as TPXGR000 - TPXGR299.
Presuming TPXGR000 - TPXGR199 are assigned for logons to the CICS(TOR) and
TPXGR200 - TPXGR299 for logons to theCICSAOR region.

Here are the steps to follow:

- Create a virtual terminal masking table -  call it CICS. 
- Create 2 entries -  say CICSTOR and CICSAOR

Masking Rules Table: CICS

Masking Rules Table Entry

CICSAOR
CICSTOR

- In the entry for CICSTOR define

Masking Rules Table: CICS
Masking Rules Table Entry: CICSTOR

Physical Terminal     Virtual Terminal
Masking Rule          Masking Rule
--------               TPXGR0
--------               TPXGR1--

- In the entry for CICSAOR define

Masking Rules Table: CICS
Masking Rules Table Entry: CICSAOR

Physical Terminal       Virtual Terminal
Masking Rule            Masking Rule
--------                TPXGR2--

In the ACT (Application Characteristics Table) for CICS(TOR)  define CICSTOR as masking rule
In the ACT (Application Characteristics Table) for CICS(AOR)  define CICSAOR as masking rule.

Define VMSK=CICS in the TPX procedure OR 
use SMRT - 10 Startup Parameters to define CICS as masking table.

Recycle TPX

TPX will now use TPXGR000 - TPXGR199 for CICS(TOR) and TPXGR200 - TPXGR299 for CICS(AOR).
TPX will select the first available VT within these ranges.

Be advised that a TYPE=UNQ VT can only have one session whereas a TYPE=GRP VT can share multiple sessions to different applications.