Establishing connection with the XRF complex

To establish a session with IMS in an XRF complex, your logon request must include either the USERVAR name you defined in the USERVAR tables or the MNPS ACB name shared by both of the IMS systems in the XRF complex.

In the case of XRF with USERVAR, VTAM® matches the USERVAR logon message to the IMS application that is currently active. For XRF with MNPS, VTAM links directly to the active IMS's MNPS ACB.

If you use XRF with USERVAR, SLU P terminal programs cannot use the APPLID name in the PLUNAME field of the BIND to reestablish a session with IMS. Instead, SLU P terminal programs must use the USERVAR in the user data field of the BIND. This restriction does not apply to XRF with MNPS, because this type of XRF system does not use a USERVAR.

SLU P systems are normally defined as class-1 terminals; in most cases in an XRF complex, when an alternate IMS takes over processing from an active IMS, the takeover is accomplished without losing class-1 terminal sessions. The terminals might or might not be aware of the takeover.

If you are connecting the 4730 Personal Banking Machine to an XRF IMS as a SLU P device, use the following machine data configuration options:

Invalid message: 10 or 11
Multiple commands: 10 or 11

The first digit (1) prevents the 4730 from sending an exception response to certain network messages, including the DFS3861 message sent after an XRF takeover. Exception responses to these messages terminate the SLU P session between the 4730 and IMS. The second digit (0 or 1) indicates whether errors should be logged.

Related reading: For more information on the 4730, see IBM® 4730 Personal Banking Machine Operations Support Manual.