Step 11: Define Interactive Debug Facility to VTAM

If you plan to conduct IDF debugging via VTAM® sessions with your terminals, you must define the minor node names for IDF to VTAM. A minor node is defined by using the following naming convention:
  • The first five characters must be ASMTL
  • The last three characters must be consecutive 3-digit numbers, starting with 001

IDF uses the ASMTLnnn minor node names for internal processing. These names are not the terminal LU names that are specified by the user in the LUNAME invocation parameters.

The number of minor node names defined must be sufficient to allow for the maximum number of concurrent IDF users using VTAM terminal sessions. You can define up to 999 minor node names for IDF.

To place the statements into a new member, take the following steps:
  1. Create a new member in the VTAM definitions library (VTAMLST).
  2. Update the new member with the required definitions.
  3. Add the new member's name to the VTAM start options configuration file, ATCCONxx.
To place the statements into an existing member, take the following steps:
  1. Select a member in the VTAM definitions library (VTAMLST) that contains the major node definitions.
  2. Update the selected member with the minor node name definitions (APPL statements) for IDF.
For example, the following statements define a major node and 10 minor node names, ASMTL001 to ASMTL010. These sample definitions can be placed into a new member or into an existing member in the VTAM definitions library (VTAMLST):
ASMAPPL  VBUILD TYPE=APPL
ASMTL001 APPL  AUTH=(PASS,ACQ),PARSESS=NO
ASMTL002 APPL  AUTH=(PASS,ACQ),PARSESS=NO
ASMTL003 APPL  AUTH=(PASS,ACQ),PARSESS=NO
ASMTL004 APPL  AUTH=(PASS,ACQ),PARSESS=NO
ASMTL005 APPL  AUTH=(PASS,ACQ),PARSESS=NO
ASMTL006 APPL  AUTH=(PASS,ACQ),PARSESS=NO
ASMTL007 APPL  AUTH=(PASS,ACQ),PARSESS=NO
ASMTL008 APPL  AUTH=(PASS,ACQ),PARSESS=NO
ASMTL009 APPL  AUTH=(PASS,ACQ),PARSESS=NO
ASMTL010 APPL  AUTH=(PASS,ACQ),PARSESS=NO

Configuring the TN3270 Telnet Server to access the terminal LUs

If you use the z/OS® Communications Server for TN3270 Telnet Server to manage your terminals, you must configure TN3270 Telnet Server to support terminals and the configuration must meet the following requirements:
  • You must access the terminal LUs that have a proper DLOGMOD parameter specified.
  • You must specify the LUMAP KEEPOPEN statement so that VTAM allocates the ACB for the terminal LU when a terminal emulator session is connected to the terminal LU, rather than only when an application is started.
  • The terminal LU name must be available to the user of the terminal emulator session.
Alternatively, you can set up a new TN3270 Telnet port to enable terminal support. Here is an example of the VTAM definition for a TN3270 Telnet port:
BEGINVTAM
 PORT 2023 
 USSTCP USSCOPS 
 ; Define the VTAM terminal LUs to use for this port
 LUGROUP ASMIDF
     ASMLU001..ASMLU050 
 ENDLUGROUP 
 IPGROUP EVERYONE
     0.0.0.0:0.0.0.0
 ENDIPGROUP 
 ; Indicate that the ACBs are always allocated 
 LUMAP ASMIDF EVERYONE KEEPOPEN 
 ; Allow only HLASM IDF to use this port 
 ALLOWAPPL   ASMTL*
ENDVTAM