Data Reception; Control Panel - Brother MP-21C Service Manual

2.3 Main PCB
2.3.1

Data Reception

IEEE1284 bi-directional nibble mode is supported. The data reception operation is
performed by the gate array. The CINT-N signal from the gate array indicates the
reception of data to the CPU and control data is processed by the CPU. The printing
data is transmitted directly to the memory without being transmitted to the CPU.
2.3.2

Control Panel

The control panel controls two switch signal inputs and four LEDs. Two out of four LEDs
correspond to each of the ink cartridges. The cover switch is contained in the switch
panel. When this switch is OFF, the cover is open and printing is disabled. However,
operations associated with cartridge replacement with the cover open are allowed.
SW 1 on the Main PCB functions as the
and turns off the LEDs, but does not turn the power off.
ONLINE / Power SW
Purge SW
Maintenance
unit
#4
CPU
IPINT-N
CINT-N
CPU
P2
MHP Sensor
II-5
#7 #8
SRAM
G/A
Fig. 2.4
(On/Off) button and stops all the operations
P7
5
11
10
9
8
Fig. 2.5
P8
Parallel
I/F connector
19 SELECT IN-N
INPUTPRIME-N
18
COVER SW
LED POWER
LED ALARM
LED INKBC
LED INKMY