The only difference between the two mounts = the Camera Depth (5mm delta):
C-Mount Camera Depth (Mount Face to Image plane) = 17.52mm
CS-Mount Camera Depth (Mount Face to Image plane) = 12.52mm
FYI – You can use any standard C-Mount lens on a CS-Mount Camera by simply employing a 5mm extension tube. However, you can not use a standard CS-Mount lens on a C-Mount Camera. All other aspect aspects of the CS-Mount are the same as the C-Mount specification.