Xerox WORKCENTRE 3119 Service Manual page 132

General Procedures and Information
Firmware Overview
The Engine Control firmware is executed every 10msec by the timer interrupt of the main system.
And consists of 4 control modules. Power on Initial, Engine Print Processing Control, Print Inter-
face Control and Engine Unit Control Module. Major operations which are controlled by the Printer
Engine Control Firmware are:
• Pick-Up, Feeding and Discharging of Paper
• LSU operations
• HVPS for the Developer Process
• Temperature of Fuser unit
• Motor operations
Power on Initial Module
IWhen the mains for the printer is turned on, the main firmware wakes the module of the engine
first and executes the necessary initialization. Then, the other modules of the printer engine con-
trol firmware are checked and initialized especially the hardware ports or variables related to crit-
ical actions.
Engine Print Processing Control Module
The main control module consists of 4 sub functions:
• Virtual timer function
This is about the virtual timer used to control time processes in the engine part. This con-
sists of three separate processes:
1) Declares the ID and Function.
2) Runs the timer and the execute functions.
3) Stops the timer. This controls the process unit as time.
• Time Processing function
This is function that processes a timer for counter, elapsed time after on time.
• Jam Processing function
It checks the jam state under conditional status.
• State processing function
This is about the processing of the engine status. This controls the printer according to the
state of the engine. These states consist of many states according to the engine mode.
Print Interface Module
The Print Interface Control Module receives commands from the main system and transmits the
present status of the engine as requested. It also calls up other sub-functions for specific opera-
tions requested by the printer controller.
Engine Unit Control Module
• Engine Unit Control Module consists of 4 sub-functions.
• Regulating temperature
• Fan control
• Sensor status management
• Unit and Devices Control (Motor, Clutch, etc.)
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