Cmx Controller Board - IBM 6400 Maintenance Information Manual

CMX Controller Board

The heart of the printer is the CMX controller board, which monitors and
directs all printer functions. The controller board receives and processes all
data from the host computer, builds the printable images, controls all motors,
and drives the hammer springs. Except for the power supply and final
hammer drive circuits, all logic and drive circuitry for the printer are contained
on the controller board.
The CMX controller board consists of two functional units: the Data Controller
(DC) and the Engine Controller (EC).
The DC is responsible for:
•
Host I/O
•
Operator I/O
•
Security Interface
•
Print Image Generation
•
Overall High Level (Logical) Control
The EC is responsible for:
•
Print Mechanism Operation
•
Print Mechanism Fault Monitoring
•
Power Shutdown/Power Saving Modes
The EC and DC communicate through semaphore registers. The DC receives
host and operator input and returns dot images and LCD messages to buffers
in memory. Image data are passed to the EC upon request, are processed,
then sent to the hammer bank. The EC synchronizes paper, ribbon, platen,
and shuttle motion as it feeds dot data to the hammer drivers. Figure 17
summarizes this architecture.
Printer Electronics
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