Host Interface Circuit; Drawer Kick-Out Drive Circuit - Epson TM U200D - B/W Dot-matrix Printer Technical Manual

Host interface circuit

The printer has the universal interfaces for connection to the host computer. There are three
kinds of the interfaces:
EIA/TIA RS-232 Interface (TM-U200D)
IEEE 1284 Interface (*1) (TM-U200PD)
(*1) Copyright 1994 by the Institute of Electrical and Electronic Engineers, Inc.
EIA/TIA RS-485 Interface (option)
Refer to the Interface Circuit Board Diagrams in the Appendix.

Drawer kick-out drive circuit

Activating the DKD1 and DKD2 signals from the CPU (U5) causes the transistors Q29 and Q30
to be turned On. This causes then transistor array QM5 to be turned 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.
The +24V drawer power supply is supplied via the regulator IC (U2), which cuts off the supply
in case of excessive current.
DKD
CN2
1
FG
2
DKD 1P
3
DKD SW
4
{24V
5
DKD 2P
6
SG
Rev. B
QM5
1
9 8
7 6
5 4
3 2
1
0
U2
VI VO
G
N
+ +
D
C16
C45
DC 24-30V IN
Figure 2-22 Drawer kick-out drive circuit
TM-U200D/U200PD Technical Manual
{5 V
D8
Q29
Q30
D8
R47
{5 V
D46
R48
R28
Q34
D2
C39
Mechanism Configuration and Operating Principles
U5
62
P32
63
P33
{5 V
R13
10
P63