HP LaserJet Enterprise 500 Maintenance Manual - Page 224

Controller and the EC Engine Controller.

Page 224 highlights

Chapter 7 CMX Controller Board 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 DC (Data Controller) and the EC (Engine Controller). The DC is responsible for: • Host I/O (Input/Output) • 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 51 summarizes this architecture. 224

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224
Chapter
7
CMX Controller Board
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 DC (Data
Controller) and the EC (Engine Controller).
The DC is responsible for:
Host I/O (Input/Output)
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 51
summarizes this architecture.