This appendix is an answer to the question “What if more input or output lines are needed ?”. Model detailed in the book carries the mark CPM1A-10CDR-A and is taken as an optimal for it’s price and features. Alternative models with greater number of lines include CPM1A-20CDR-A, CPM1A-30CDR-A or CPM1A-40CDR-A. The last two can be expanded with three additional modules with 20 extra I/O lines each, totaling 100 I/O lines as a maximum (if this is still insufficient, maybe it is time for you to start using some of more powerful PLC controllers).
If not even the most powerful model of CPM1A family satisfies your needs, then extra modules with 20 I/O lines are added. This form of connection reaches 100 input/outputs, which is a significant number in industrial proportions.