Service manual

2-22 Mechanism Configuration and Operating Principles Rev. B
Confidential
A near-end detector is an option that detects the remaining amount of a paper roll. The input
signal to the CPU (U5) becomes LOW when a paper near-end is detected.
Host interface circuit
The printer has universal interfaces for connection to the host computer. There are three kinds of
interfaces:
❏
EIA/TIA RS-232 intrface
❏
IEEE 1284 interface
❏
EIA/TIA RS-485 interface
See the interface circuit board diagrams in the Appendix.
Drawer kick-out drive circuit
Activating the DKD1 and DKD2 signals from the CPU (U5) causes transistors Q29 and Q30 to
turn on. This causes transistor array QM5 to turn on, and the drawer drive signal is output. The
drawer status signal DK_S, which indicates whether or not the drawer is open, is input to the
CPU (U5), allowing the host to check the status via the interface.
Figure 2-22 Various detector circuits
4
3
1
2
CN8
4
2
3
1
1
2
2
1
CN11
R40
R37
R39
R16
R36
R38
C23C22 C46
R53
Mechanism 1
Mechanism 2
C44
+5V +5R
GND
NEC
HPC
REC
NE
HP DET
RE
P62/AN2
12
P64/AN4
9
11
P65/AN5
U5
12
12
GND
+5V
R.E
H.P
N.E
GND
Printer mechanism
+5V