2.3 Control Circuit Operation
The control circuit consists of two circuit boards: the
MAIN (the main control circuit board) and the
PNL (the control panel circuit board). This section describes the operation of these boards.
2.3.1 Control Circuit Operation Overview
The CPU on the
MAIN is the 8-bit TM
microprocessor (9.83 MHz). It oversees control of all the
components of the printer. The E05A66YA gate array contains various memory management functions that
control the memory assignment and
areas. The output signals from each detector are sent to the analog
input
of the CPU. The signals from the control panel are sent to the gate array, which in turn sends LED
signals to the control panel. The two motors (CR and PF) are controlled by signals sent from the stepping
motor control port of the CPU. Figure 2-23 shows the control circuits in block diagram form.
4K
BIT
5C1
I
)
1
CONTROL
PANEL
AND LEDS
PG
PE FRONT
.
PE REAR
RELEASE
SENSOR
SENSOR
SENSOR
LEVER
SENSOR
1
CR
HOME
SENSOR
HEAD
THER-
MISTOR
D a t a b u s
b u s
Figure 2-23. Control Circuit Block Diagram
2-22
Summary of Contents for FX 1170 - B/W Dot-matrix Printer
Page 1: ...EPSON EPSON TERMINAL PRINTER FX 870 1170 SERVICE MANUAL 4001461 REV A ...
Page 5: ... f REVISION SHEET REVISON DATE ISSUED CHANGE DOCUMENT A June 15 1992 1st issue 7 v ...
Page 11: ...REV A 4 80 column model 136 column model Figure 1 1 External View of the FX 870 1170 r 1 2 ...
Page 128: ...REV A Figure 6 1 Lubrication Points 6 3 ...
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