Controller Board - Printronix P5000 Maintenance Manual

Controller Board

The heart of the printer is the controller board, which monitors and directs all
printer functions. ASCII and P5XKA printers use a controller designated the
CMX controller board. H-Series printers use a controller designated the CFX
controller board. These boards differ in certain details of circuit design and
layout. Functionally, they are nearly identical, but they are not
interchangeable. ASCII and P5XKA printers must use the CMX controller
board, while H-Series printers must use the CFX controller board.
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 controller board consists of two functional units: the DC (Data Controller)
and the EC (Engine Controller).
The DC is responsible for:
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The EC is responsible for:
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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 56
summarizes this architecture.
Host I/O (Input/Output)
Operator I/O
Security Interface
Print Image Generation
Overall High Level (Logical) Control
Print Mechanism Operation
Print Mechanism Fault Monitoring
Power Shutdown/Power Saving Modes
Ribbon Transport System
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