Figure 1 shows four interactive programs. A1 is a top-level program started by, for example, a terminal end-user. It isn't started by a program and doesn't have a current channel. B1, B2, and B3 are all second-level programs.
B1's current channel is X, passed by the CHANNEL option on the EXEC CICS LINK command issued by A1.
B2 has no current channel, because B1 doesn't pass it one.
B3's current channel is Y, passed by the CHANNEL option on the EXEC CICS XCTL command issued by B2.
The table below lists the name of the current channel (if any) of each of the four programs shown above.
Program | Current channel | Issues command |
---|---|---|
A1 | None | . EXEC CICS LINK PROGRAM(B1) CHANNEL(X) . |
B1 | X | . EXEC CICS XCTL PROGRAM(B2) . |
B2 | None | . EXEC CICS XCTL PROGRAM(B3) CHANNEL(Y) . |
B3 | Y | . EXEC CICS RETURN . |