Setting limits for virtual terminals

From the Edit IMSID Options panel, type 2 in the selection field and press Enter.The IMSID Options – VT Limits panel is displayed.

The following fields are available on this panel:

IMSID

The IMSID of the options module that you selected. This is not an editable field.

Maximum /SECURE ALLOWed users

The maximum number of user IDs that can be specified by a /SECURE ALLOW command between IMS cold starts.

DELTA PLUS VIRTUAL TERMINAL uses this value to calculate the size and capacity of the userid pool, VTFUSBPL, which is allocated in the IMS private area during initialization. This value is optional; 0 indicates that no userid pool is allocated.

If this value is too low, it can cause /SECURE ALLOW commands to fail. If this value is too high, it can waste private area virtual storage, but it will not create more overhead.

The initial value is site-dependent. Although you may increase the value without impacting IMS operation, it will not take effect until the next IMS restart. A cold start is recommended if you decrease the value.
Maximum virtual printer overrides

The maximum number of virtual printer overrides in effect at the same time that can be specified by an /ASSIGN command.

DELTA PLUS VIRTUAL TERMINAL uses this value to calculate the size and capacity of the VPO pool, VTFVPOPL, which is allocated in the IMS private area during initialization. This value is optional; 0 indicates that no VPO pool is allocated.

If this value is too low, it can cause /ASSIGN commands for virtual printers to fail. If this value is too high, it can waste private area virtual storage, but it will not create more overhead.

The initial value is site-dependent. Although you can increase the value without impacting IMS operation, it will not take effect until the next IMS restart. A cold start is recommended if you decrease the value.

Maximum virtual terminal pending entries

The maximum number of virtual terminal pending entries that can be in effect at the same time.

This value is ignored when Resource Manager (RM) and IMSPLEX Terminal Management are in use.

DELTA PLUS VIRTUAL TERMINAL uses this value to calculate the size and capacity of the VTE pool, VTFVTEPL, which is allocated in the IMS private area during initialization. 0 indicates that no VTE pool is allocated.

If this value is too low, it can cause virtual terminal /EXCL, /STOP, /TRA, or /TEST MFS commands to fail. If this value is too high, it can waste private area virtual storage, but it will not create more overhead.

You can change the value without impacting IMS operation, but it will not take effect until the next IMS restart. A cold start is recommended if you decrease the value.

Idle terminal logoff intervals

The number of minutes a virtual terminal can remain inactive before an automatic logoff is invoked. The logon/signon process can select the alternate interval. For more information about automatic logoff, see the DELTA PLUS User Guide.

A valid terminal logoff interval is 0 or a value between 10 and 999 minutes.

Idle conversation logoff intervals

The number of minutes a virtual terminal in conversational mode can remain inactive before an automatic logoff is invoked. This value overrides the idle terminal logoff interval specified in the previous field if the terminal is in conversational mode.

When a virtual terminal is logged off, conversations are assigned to the user/SPQB that was created when the terminal was logged on. The conversations remain in the state they were in when the terminal was logged off. This option only logs off the terminal; it does not exit the conversations.

The logon/signon process can select the alternate interval. For more information about automatic logoff, see the DELTA PLUS User Guide.

A valid logoff interval for a terminal in conversation is 0 or a value between 10 and 999 minutes.

Idle virtual printer logoff intervals

The number of minutes a virtual printer can remain inactive before an automatic logoff is invoked. You can specify use of the alternate interval via the virtual printer timer override. For information about creating TSS tables, see the DELTA PLUS User Guide. The alternate value, entered in minutes, specifies how long a virtual printer may remain inactive before an automatic logoff will be invoked.

Virtual printers that use models defined to IMS with OPTIONS=DISCON are automatically logged off when the queue count is zero. The OPTIONS=DISCON parameter takes precedence over any value that you specify in this field. This option also takes precedence over the No Automatic Timeout option in a Virtual Printer Timer Override table.

Held conversation exit interval

This field is optional. The number of minutes a virtual terminal waits before exiting a held conversation, whether the conversation was initiated and held on a virtual terminal or an IMSGEN-defined terminal. 0 indicates that no held conversations are to be exited.

Held conversations can be exited only if the terminal is stopped or disconnected.

This interval is independent of the idle conversation logoff intervals; it does not begin after the expiration of the idle conversation logoff interval. For example, if a held conversation exceeds the held conversation exit interval while still assigned to an active terminal, the conversation will be immediately exited when the terminal logs off or is automatically logged off due to inactivity.