NIB fields set by VTAM

The NIB operands already described are supplied by the application program and cause the NIB fields to be set when the NIB macroinstruction is assembled. Additional NIB fields are set by VTAM®; these fields can be examined by the application program during program execution. (Some of these fields can also be set by the application program.) VTAM uses these fields to return information to the application program upon completion of processing for OPNDST, OPNSEC, and OPEN (for a CNM application program). These fields are:

Field name

Contents

CID

A field containing a 32-bit value identifying the session established by using this NIB. This communication ID (CID) is also placed in the ARG field of the RPL used by the OPNDST or OPNSEC macroinstruction (if one, and only one, session was established). When NIB lists are used, the CID placed in the ARG field is not meaningful. The CID can be examined with the SHOWCB and TESTCB macroinstructions or with the ISTDNIB DSECT. See Control block formats and DSECTs, for more information. (If the session is not established, the CID field is not modified.) This field can be set by VTAM or the application program.

Note: The algorithm used to construct the CID can vary between releases of VTAM. Therefore, the application program should not become dependent on any perceived values.

CON

An indicator that is set to show that the session represented by this NIB has been established. You can examine this field following OPNDST or OPNSEC by coding CON=YES in a TESTCB macroinstruction; an “equal” PSW condition code indicates that the CON field is set to YES, and the session is established. This field is useful if you are using OPNDST with a list of NIBs to establish more than one session. Examination of each NIBCON field tells you which sessions were successfully established and which were not. This field is set to NO if the session is not established. This field is set only by VTAM.

Note: You must check the CON field to determine if the session was actually established. A return code indication is not sufficient.

DEVCHAR

An 8-byte field describing certain characteristics of the SLU in the session established by OPNDST. (If the session is not established, the DEVCHAR field is not modified.) This field can be examined with either the SHOWCB or TESTCB macroinstruction or with the ISTDVCHR DSECT. The ISTDVCHR DSECT is described in Control block formats and DSECTs. This field is set only by VTAM.

NIBNACLQ

An indicator that is set to show whether a CINIT is still queued after an OPNDST OPTCD=ACCEPT macroinstruction fails to accept that queued CINIT. If this bit is on (1), it means that the queued CINIT was canceled by VTAM. The session-initiation request must be repeated; for example, a terminal operator has to log on again. If the bit is off (0), an error was detected prior to finding a pending active session with a matching CINIT. Refer to RPLRTNCD and RPLFDB2 for specific error recovery actions.

NAME

An 8-byte field containing the name of the secondary logical unit with which OPNDST OPTCD=(ACCEPT,ANY) has established a session. The NAME field is also filled in if OPNDST or OPNSEC uses the NIB CID field to identify a pending active session; in this case also, the name is that of the session partner LU. This field can be set by VTAM or the application program.

NETID

The name in the network where the session parameter LU resides.

NIBPSPLU

An indicator that shows whether the application is a PLU or an SLU for a particular session. A setting of 1 indicates that the application program is a PLU; 0 indicates that the application program is an SLU. INQUIRE OPTCD=PERSESS and OPNDST OPTCD=RESTORE provide the information.

NIBPSRSP

An indicator that shows the RESP data mode of the session pending recovery. A setting of 0 indicates that the RESP data mode is continue any at the time that the session is retained. A setting of 1 indicates the data mode is continue specific. INQUIRE OPTCD=PERSESS and OPNDST OPTCD=RESTORE provide the information.

NIBPSDFS

An indicator that shows the DFSYN data mode of the session pending recovery. A setting of 0 indicates that the DFSYN data mode is continue any at the time the session is retained. A setting of 1 indicates the data mode is continue specific. INQUIRE OPTCD=PERSESS and OPNDST OPTCD=RESTORE provide the information.

NIBPSDFA

An indicator that shows the DFASY data mode of the session pending recovery. A setting of 0 indicates that the DFASY data mode is continue any at the time the session is retained. A setting of 1 indicates the data mode is continue specific. INQUIRE OPTCD=PERSESS and OPNDST OPTCD=RESTORE provide the information.

NIBRPARM

An address that points to the restore parameter list. The first word points to the portion of the BIND for the session being recovered that is mapped by ISTDBIND. The second word of this parameter list points to the session state control vector information for the session being recovered.

NIBSLWRK

Indicates SIMLOGON was successful for this NIB.

NIBNNAMS

Indicates that the association established with a partner LU is known by the application's network name.

NIBAFFIN

When the LUAFFIN parameter has been specified on the NIB for an OPNDST RPL or an OPNSEC RPL, the value NIBAFFIN will be set upon completion of the RPL to indicate whether VTAM owns the affinity or the application owns the affinity. If NIBAFFIN is set on, it indicates that the application owns the affinity.