The Register Module contains the system's I/O Data Table. The data table is divided into three areas; the I/O Status Table, System Status Table, and the Register Tables.
The I/O Status Table contains either 2048 (2K x 2K) or 4096 (4K x 4K) continuous single bit storage locations which have a starting address of O. In the 2K x 2K Register Module 2048 single bit locations are available for real I/O status or internal coils. In the 4K x 4K Register Module 2048 locations are available for real I/O status or internal coils, and an additional 2048 locations are available for internal coils.