The figure below shows the same four interactive programs described in Current channel example, with XCTL commands, plus a third-level program, C1, that is invoked by an EXEC CICS LINK command from program B1.
The scope of the X channel is restricted to A1 and B1.
The scope of the Y channel is B2 and B3.
The scope of the Z channel is B1 and C1.
Note that, by the time control is returned to program A1 by program B3, it's possible that the X channel may have been modified by program B1—it might not contain the same set of containers as when it was created by A1.
The table below lists the name and scope of the current channel (if any) of each of the five programs shown in the figure above.
Program | Current channel | Scope of channel |
---|---|---|
A1 | None | Not applicable |
B1 | X | A1 and B1 |
B2 | None | Not applicable |
B3 | Y | B2 and B3 |
C1 | Z | B1 and C1 |