Sample model major node

In the following sample you do not need to code LU statements following a PU statement.

MODEL    VBUILD TYPE=MODEL              MODEL MAJOR NODE
SPUMOD02 PU    ADDR=02,                 PU STATION ADDRESS
               MAXDATA=256,             MAX BYTES PU RECEIVES IN ONE PIU
               PUTYPE=2,                PU TYPE
               MAXOUT=1,                MAX PIUS WITH NO REPLY
               IRETRY=NO,               NCP RETRY
               DISCNT=YES,              DISCONNECT AT SESSION END
               ANS=CONTINUE             CONTINUE DURING NCP ANS
SPUMOD01 PU    ADDR=01,                 PU STATION ADDRESS
               MAXDATA=256,
               PUTYPE=2,
               MAXOUT=1,
               IRETRY=NO,
               DISCNT=YES
GROUP1   GROUP PACING=(1,1),    PACING LU AND BOUNDARY NODE
               VPACING=2        PACING VTAM AND BOUNDARY NODE
SPUMOD   PU    ADDR=03,          
               MAXDATA=256,      
               PUTYPE=2,         
               MAXOUT=1,         
               IRETRY=NO,        
               DISCNT=YES
SLUMOD01 LU    LOCADDR=1,        LU LOCAL ADDRESS
               MODETAB=MODETAB2  LOGON MODE TABLE NAME
SLUMOD03 LU    LOCADDR=3,        LU LOCAL ADDRESS
               MODETAB=MODETAB2
SLUMOD02 LU    LOCADDR=2         LU LOCAL ADDRESS

Note: The PACING and VPACING values coded on the GROUP statement do not sift down to SPUMOD. SPUMOD gets the default values for PACING and VPACING. PACING and VPACING sift down to the LUs from the GROUP, but they would not have sifted down from the PU if they had been specified there.

A PU on a switched line is identified by the device CPNAME or IDBLK and IDNUM. As soon as a dial-in line has been activated and placed in answer mode (during VTAM® startup or by the VTAM operator), the physical unit can dial the line number and establish communication with VTAM.

When the dial-in connection is broken, the devices are deactivated and the PU and LU definitions in the dynamic switched major node are deleted. When the last PU within the dynamic switched major node is deleted, the switched major node is also deleted.

Coding DISCNT=YES causes the connection to be broken after all sessions using the line have ended. If you code DISCNT=YES on your model PU statements, consider the cost of the line and the number of session starts and ends this particular device will have.

Restriction: Dynamic definition of switched connections is for dial-in use only. VTAM has no knowledge of the path definitions. Therefore, should the line drop, even if the device is active, VTAM cannot use the definition for dial-out operations. The sole exception to this rule is for a model PU defined for Enterprise Extender with DYNTYPE=EE and DWINOP=YES coded. In this case, if the EE connection is dropped, VTAM will attempt to dial back out to the partner using the remote IP address and remote SAP sent inbound when the connection was established. The configuration restart files are not updated with dynamic definitions.

In environments with an owning and backup host, the backup host can also implement a configuration services XID exit, and dynamically create resource definitions during takeover of NCPs that have dial-in resources connected to them. The backup host exit is provided the same information during takeover that is provided to the exit during a dial-in operation.