Repair manual

2-48
THEORY OF OPERATION
8. Digital Palette Operations
a. Camera Back Control
The Digital Palette supports a number of different camera backs:
35mm, Pack Film, Auto Film, and 4 x 5. The user can routinely change
from one camera to another. Each camera back can accept one or more
different types of films. The Camera Back Control circuit indicates which
type of camera is currently attached, but the host computer software must
set a parameter to indicate the type of film that is loaded in the attached
camera. If the film parameter set by the host computer software is
inappropriate for the attached camera, the computer Imager will not allow
a picture or slide to be taken. The film parameter that is appropriate for
the attached camera must be set by the host computer software. Refer to
the Digital Palette Product Specification Manual for detailed parameter
information.
The Camera Back Control circuit is also responsible for opening and
closing the applicable camera shutter and automatically advancing a
motorized type camera back (35mm and Auto Film) to its next film
frame after an exposure is completed. For non-motorized camera
backs (Pack Film and 4 x 5), the user must manually remove the
exposed film.
1) Camera Back Inquiry
The Camera Back Control Circuit (Figure 2-9, sheet 5, upon
command from an Inquire Camera command from the host
computer, indicates the type of camera that is attached to the
Digital Palette. This circuit sends a 1-byte code followed by an
ASCII string describing the camera currently attached to the
Digital Palette to the host computer via the applicable parallel
interface. The system camera default type is Pack Film. If no
camera is attached to the Digital Palette, a code (Table 2-11)
indicating a Pack Film camera type will be reported when the
host computer inquires about the camera type prior to the start
of an exposure cycle.