Criteria for selecting a default logon descriptor

IMS provides a default logon descriptor for each VTAM® terminal type. The logon descriptor name is based on the LU type and TS profile.

If necessary, you can add logon descriptors. If you do not provide a logon descriptor, and IMS does not locate one in IMS.PROCLIB or in the Logon exit routine (DFSLGNX0), IMS uses the algorithm shown in the following table to assign a default logon descriptor name. The VTAM LUTYPE, IMS UNITYPE, and IMS default logon descriptor names are shown for each terminal type.

The default logon descriptor is determined in one of three ways:
  • IMS looks for the most common logon descriptor created during IMS system definition and uses it as the default.
  • If no terminal definition exists for that terminal type, IMS creates a default logon descriptor.
  • Your installation can create a default logon descriptor.
Table 1. Mapping for VTAM LUTYPE, IMS UNITYPE, and default logon descriptor names
VTAM LUTYPE IMS UNITYPE Default descriptor name
X'06' LUTYPE6 DFSLU61
X'02' SLUTYPE2 DFSSLU2
X'01'

SLUTYPE1 (Default)1
NTO

DFSSLU1
DFSNTO

X'00'
(TS = X'04')

SLUTYPEP (Default)2
Finance
3601

DFSSLUP
DFSFIN
DFSFIN

X'00'
(TS = X'02' or X'03')

3270
3270, UNIT=3284

DFS3270
DFS327P
Notes to table:
  1. IMS does not distinguish between SLUTYPE1 and NTO terminals; SLUTYPE1 is the default. To support both SLUTYPE1 and NTO terminals, do the following:
    • Override the DFSSLU1 default logon descriptor by using the Logon exit routine (DFSLGNX0) or by specifying the LOGOND parameter.
    • If your installation has no SLUTYPE1 terminals, rename the DFSNTO logon descriptor to DFSSLU1 in order to make it the default for LU type X'01' terminals.
  2. IMS does not distinguish between SLU type-P, Finance, and 3601 terminals; SLUTYPEP is the default. ETO considers Finance and 3600 series terminals to be the same. To support both SLUTYPEP and 3600/Finance terminals, do the following:
    • Override the DFSSLUP default logon descriptor by using the Logon exit routine (DFSLGNX0) or by specifying the LOGOND parameter.
    • If your installation has no SLUTYPEP terminals, rename the DFSFIN logon descriptor to DFSSLUP in order to make it the default for LU type X'00' (TS = X'04') terminals.