Delayed activation of logical lines

This function enables you to perform an orderly activation of a physical resource and its associated logical resources. Because there is a hierarchical relationship between the physical resources (line and physical unit) and the logical lines, you can use this function to implicitly activate a logical line when the physical resources are explicitly activated.

The function creates a hierarchy between a logical line in a group (within an NCP major node) that has a PHYSRSC operand coded and the physical resource indicated by the PHYSRSC operand. This includes:

NCP token-ring interconnect (NTRI) physical resources (line and physical unit) and logical lines for INN link stations
NCP Packet Switched Interface (NPSI) physical resources (line and physical unit) and logical lines
Frame relay nonswitched and switched physical resources (line and physical unit) and logical lines

Lines within any line group for which the PHYSRSC operand is coded are logical lines. Lines within a line group for which PHYSRSC points to a valid physical unit within the same NCP major node are hierarchically subordinate to the physical unit. Not all logical lines are hierarchically subordinate to a physical resource. Because an NTRI switched peripheral line can be used serially for connections through different token-ring interface couplers (TICs), lines within a line group where the PHYSRSC, ECLTYPE, and DIAL=YES operands are coded are not subordinate to the physical unit. In this case, VTAM® does not create the hierarchy between the physical resources and those logical lines. PHYSRSC must point to a physical unit to create the subordinate logical line relationship.

Activating logical lines hierarchically: A subordinate logical line can be activated only after its higher-level physical unit has been activated. The SCOPE operand on the VARY ACT command works with this hierarchy like it does with other hierarchical relationships in VTAM. For example, SCOPE=ALL on the higher-level physical unit causes the subordinate logical lines and their subordinate resources to be activated. SCOPE=U causes only the logical lines with ISTATUS=ACTIVE (and any subordinate resources with ISTATUS=ACTIVE) to be activated. SCOPE=COMP and SCOPE=ONLY also work with this hierarchy.
Deactivating logical lines hierarchically: When a logical line is subordinate to the physical resource, deactivation of the physical resource deactivates the logical lines.