Epson EPL-N4000 - Printer Control

EPSON EPL-N4000/EPL-N4000+ Chapter 2 Operating Principles
Rev.B 79
2.7 Printer Control
Printer Control is a broad term that is used to describe the printer
resources that monitor and control the actions and operations of the
printer; from warm-up, throu
g
h the print cycle, to machine error
detection.
The center of printer control for the printer base en
g
ine is the Machine
C
ontrol Unit PWB, or MCU PWB. The MCU contains an 8 bit
microcomputer. The MCU contains ASICs (Application Specific
Inte
g
rated Circuits) for ima
g
e data transfer and communication control,
ROM, RAM, a 16 bit inte
g
rated timer, pro
g
rammable timin
g
pattern
control, a watch do
g
timer, serial communications interfaces, an A/D
converter, a D/A converter, I/O ports, and a DMA controller.
The MCU PWB provides the lo
g
ic and information processin
g
that is
necessary for the printer to function. Every electrical component within
the printer is connected either directly or indirectly to the MCU PWB.
Sensors in the printer send printer status information to the MCU. The
MCU processes that information and compares it to timin
g
tables that
are stored in onboard ROM. Actin
g
on the results of the processin
g
, the
MCU sends commands to various printer components; switchin
g
on
motors, switchin
g
off volta
g
es, si
g
nalin
g
statuses. Non-Volatile RAM on
the MCU PWB stores adjustable operation parameters, such as Fuser
temperature and laser stren
g
th, that are used as reference durin
g
printer operation.
Figure 2-38. Control Circuit Board
Controller