Samsung SCX-4200 Series Service Manual page 36

System Overview
3.3.2 S/W Overview
Engine Control F/W is executed every 10msec by the timer interrupt of the main system.
And it consists of 4 control modules. Power on Initial, Engine Print Processing Control, Print Interface Control and
Engine Unit Control Module. Major operations of the Printer Engine Control F/W are following.
- Control the Pick-Up, Feeding and Discharging of Paper
- Control the LSU
- Control the HVPS for the Developer Process
- Control the Temperature of Fuser unit
- Control the Motor
3.3.2.1 Power on Initial Module
If it turns on the power of the printer, the main f/w calls this module of the engine first. And so the printer engine con-
trol firmware executes the necessary initialization. After that, the other modules of the printer engine control firmware
are called and executed. Specially, in this module H/W ports or variables related to critical action must be initialized.
3.3.2.2 Engine Print Processing Control Module
The main control module largely consists of 4 sub functions. First function is that processes virtual timer jobs, sec-
ond function does a Time Processing for checking elapsed time and counter, the third function is that is doing jam
processing and final function is that doing state processing for the each engine state.
- Virtual timer function: This is about the virtual timer used to control time process in the engine part. This
consists of three parts. One is the action part to declare ID and Function, another is the execution part to
run the timer and the function and the other is the stop part to stop 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.
3.3.2.3 Print Interface Module
Print Interface Control Module communicates with the main system for receiving the command from main system
and transmitting the present status of engine for requested status. There are several sub functions. One is a func-
tion for receiving command from the main system. Second is a function that informs the main system of the current
engine status for requested item. And there is function that calls sub-functions for specific operations that is request-
ed by printer controller or printer engine firmware.
Service Manual
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Samsung Electronics