TSC TDP-243 Series, Service Manual

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27
TTP-243 Bar Code Printer
Service Manua
l
3.11 Communication (Serial & Parallel Port) Circuit
C1+
1
V+
2
C1-
3
C2+
4
C2-
5
V-
6
T2OUT
7
R2IN
8
R2OUT
9
T2IN
10
T1IN
11
R1OUT
12
R1IN
13
T1OUT
14
GND
15
VCC
16
U21
RS232
RX1
RX2
TX1
TX2
C61
0.1u
C62
0.1u
C63
0.1u
C64
0.1u
L8
BEAD
C13
10u
L9
BEAD
L10 BEAD
L11
BEAD
L12 BEAD
CVCC
VCC
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
JP14
CENTRONIC
CLK
3
D
2
SD
4
CD
1
Q
5
Q
6
U22A
74LS74 3 4
U11B
74LS14
R57
100
C65
220p
D0
3
Q0
2
D1
4
Q1
5
D2
7
Q2
6
D3
8
Q3
9
D4
13
Q4
12
D5
14
Q5
15
D6
17
Q6
16
D7
18
Q7
19
OE
1
CLK
11
U23
74LS374
1
2
3
4
5
6
7
8
9
10
RN4
10K
CVCC
C38
220p
C39
220p
C40
220p
C41
220p
C42
220p
C43
220p
C44
220p
C45
220p
R24
100
R25
100
R26
100
R27
100
R28
100
R29
100
R30
100
R31
100
R33
100
R34
100
R35
100
R36
100
PE
/ERROR
SELECT
VCC
DO[0..7]
DO[0..7]
DO0
DO1
DO2
DO3
DO4
DO5
DO6
DO7
CENTRONIC
INT
C71
0.1u
CGND
CGND
CGND
CGND
DIGITAL GND
DIGITAL GND
5 6
U11C
74LS14
8 9
U11D
74LS14
10 11
U11E
74LS14
12 13
U11F
74LS14
R32
100
5
9
4
8
3
7
2
6
1
JP13
DB9_1
C14 -> U22
C36 -> U23
Fig. 3.12 RS-232 (Serial Port) Circuit
The RS-232 Circuit is for use with the externally connected personal computer and
keyboard unit. JP13 connects to PC serial port through the RS-232 cable. RxD is the
data receive pin of MCU. CTS is the Clear To Send of MCU, which sends the signal
from the external device. TxD is the data output pin of MCU. RTS is the Request To
Send signal which MCU sends to the external device.
The parallel port circuit is for use with the externally connected personal computer
parallel port through the printer cable. When PC’s strobe signal comes in, the printer
responds the ‘busy status’ until it reads the data from parallel port. Printer will respond
the ‘error signal’ to PC when it is in error status.