Scope example, with LINK commands

This example adds to the diagram from Current channel example, with LINK commands to show the scope of each channel.

For more information about LINK commands, see Current channel example, with LINK commands.

The following figure shows the same five interactive programs previously described.

The scope of the X channel—the code from which it can be accessed—is programs A, B, and C.

The scope of the Y channel is programs D and E.

Start of change Neither of these channels is the transaction channel DFHTRANSACTION, the scope of which would be the whole transaction. End of change

Note that, by the time control is returned to program A by program B, the X channel has been modified—it does not contain the same set of containers as when it was created by program A.

The picture shows the scenario described in the text. — Figure 1. The scope of a channel—example showing LINK commands

The following table lists the name and scope of the current channel (if any) of each of the five programs shown in the previous figure.

Table 1. The scope of a channel—example with LINK commands
Program	Current channel	Scope of channel
A	None	Not applicable
B	X	A, B, C
C	X	A, B, C
D	None	Not applicable
E	Y	D, E