I/O Rack, Expansion, 5 Slots IC693C IC693CH IC693CHS Additional modules and features include Standard model CPUs: IC693CPU311, IC693CPU313, IC693CPU323 – Entry level applications with low I/O counts are ideal for these CPUs. The CPU is embedded into the backplane allowing all slots available for I/O. These models are compatible with advanced modules such as Ethernet, the various bus modules, and motion control.