Rack or Chassis
A chassis is the physical frame or structure of an automobile, an airplane, a desktop computer, or other multi-component device.
A Rack is the framework, typically with rails, bars, hooks, or pegs, for holding or storing things.
Q312DB - Mitsubishi
Q Universal CPU high speed base with 12 I/O slots and 1 power supply slot..
Q38DB - Mitsubishi
Q Universal CPU high speed base with 8 I/O slots and 1 power supply slot..
Q3ACPU - Mitsubishi
QnA Series High Performance Multifuction CPU, 2048 I/O Points , 92K Step Memory..