Chapter 6. Example Query Interactions

As you become familiar with how VTAM control blocks relate to one another, you will be able to use Query to diagnose increasingly complex issues within VTAM.

This chapter provides samples of how you can diagnose specific questions about a VTAM network using Query:

Determining a Session's BIND Image.

Determining an Application's Privileges.

Determining a Session's BIND Image

Let's say that you want to determine the BIND image that is being used between a particular VTAM application program (the PLU) and a device named T010001 (the SLU).

The information that you seek is a function of an existing session. VTAM stores this information in a Session Information Block (the SIB).

Steps:

1. From the Query menu, select choice 6, 'Session information blocks'; the following list would appear containing the SIBs:

   Menu of Active SIBs

   The first and second columns list the LU names of the two session partners. The third column indicates the type of control block.

2. You would then select the SIB for T01001 (choice 6), which generates the following display of the SIB (presuming that FORMAT mode is in effect):

   SIB Formatted Display

   Sibbpptr and Sibbsptr contain navigational values that point at the SIB extensions for the Logical Units in session. The field prompt of Sibblgmd contains the logmode name that was used for session setup.

3. To produce an interpretation of the BIND image, you would move the cursor to the Sibblgmd field value and press Enter. Query would respond with the following BIND image display panel:

   BIND Image Formatted Display

   The values from this Query display are related to the VTAM MODEENT macro by the identified operands (MODEENT FMPROF= is equivalent to the Binfm panel element, etc.).

   You may also interrogate the meanings of individual BIND image supplemental fields by using the cursor (see Viewing additional field information). For example, selecting the BINPRIP field would cause the following pop up to appear:

   BINPRIP Supplemental Pop Up

   The interpreted bits represent the settings that are in effect for the selected supplemental field.

4. You would then press F12 (Cancel) to return to the Logmode Table panel and press F16 (Dump) to display the control block in hexadecimal format:

   BIND Image DUMP

   If you have dealt with BIND images previously, you should recognize the BIND beginning at offset 8 in the display.

Determining an Application's Privileges

Assume that you would like to determine if a specific application is authorized for the Secondary Program Operator privilege (SPO).

This information is defined to VTAM in the VTAMLST member or file associated with defining the Application, which you can locate easily via the Resource definition table.

However, to provide a better demonstration of the connection between VTAM control blocks, we will start from the Application Program Blocks.

Steps:

1. Go to the Query Menu: [See Opening the Query Menu for steps on accessing the Query menu. ]

   Query Menu

2. Select choice 1, 'Application program blocks'; Query responds with a list of active data extent blocks (DEBs):

   Menu of Data Extent Blocks

3. Select the application that you are interested in viewing; The Network Center will respond with panel TNQFMCB, which contains the FMCB's currently associated with the DEB and the DEB itself. For this example, you would chose the "A01TNC" data extent block:

   Menu of Function Management Blocks

4. You would then select 'AO1TNC' to display the DEB fields for the A01TNC Application (each VTAM release may have a different panelid); the VTAM Data Extent Block panel appears:

   VTAM Data Extent Block for A01TNC

5. You would now be able to look for the RDT. In this case, you would have to move the display forward (F8) to the second page of the output, which contains the RDT entry address:

   VTAM Data Extent Block Second Page

   The Acdrdte field contains the address of the RDT (Resource Definition Table) entry for A01TNC.

6. You would then select the Acdrdte field by placing the cursor on it and pressing Enter; Query would reposition the display to the requested address, which happens to be the appropriate RDT entry:

   A01TNC's Resource Table Application Entry

7. You would now move the cursor to the second byte of the Rapbitan field and press Enter; this asks Query to interpret the flag bits that the cursor is positioned at:

   Interpreted Rapbitan Flags for A01TNC

   The Rapbitan flags indicate that A01TNC has several characteristics provided via the AUTH= keyword of the APPL definition. The one we are interested in (Rapaspo) is on, which means that the application is authorized for the Secondary Program Operator interface (VTAM commands can be generated by the program).