Conditional printing.

1 sandwich printer

1 pizza printer

If there is only a sandwich order It prints on the sandwich printer only.

If there is only a pizza ordered it prints on the pizza printer only.

If a sandwich and a pizza is order together on the same order then the sandwich printer prints both the sandwich and pizza and the pizza printer prints both the pizza and sandwich. Each station needs to be aware of the full order for timing reasons.

The pizza should not print on the sandwich printer if it is only a pizza is ordered. A sandwich should not print on the pizza printer if only a sandwich is ordered.

This is called conditional printing.