Intermec EasyCoder 501 – Service Manual Ed. 7
162
Chapter 20 Serial Interface Board
20.5 Circuit Diagram A
Serial Interface Board 1-971703-40
+5V
Y1
P4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
20
21
22
23
19
24
25
26
AD4
AD3
AD5
AD2
AD6
AD1
AD7
AD0
CSX0
CSX1
XINT
WR
RD
X0
X1
NMIHPC
+5.3V
GND
A4
A2
A3
/RESET
A1
GND
74AC14
5 6
IC3C
/RXDA
/TXDA
/RXDB
/TXDB
/DSRB
/DSRA
GND
GND
GND
/CTSB
/CTSA
/DTRB
/DTRA
/RTSB
/RTSA
32
33
34
35
8
9
21
6
5
3
1
19
22
18
23
17
24
16
25
31
30
10
11
37
38
39
2
36
4
7
15
26
14
27
13
28
12
29
CSX1
WR
RD
X1
A4
A3
A2
A1
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
IC1
88C681/40
C17
C16
GND
3.6864 MHz
1
X1
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
47k
10
2
5
3
6
4
7
9
8
RN2
RN1
CSX1
WR
RD
/DTRA
A4
A3
A2
A1
47k
8
9
10
5
3
7
6
4
2
1
X1/CLK
X2
RESET
CS
WR
RD
INT
A3
A2
A1
A0
D7
D6
D5
D4
D3
D2
D1
D0
RXDA
TXDA
RXDB
TXDB
I 6
I 5
I 4
I 3
I 2
I 1
I 0
07
06
05
04
03
02
01
00
IC2
RXDA
CTSA
DSRA
MC145407
–
CEXT
+
–
CEXT
+
+10V
–10V
TXDA
RTSA
DTRA
1
+
+
1
3
20
18
11
13
15
16
14
12
17
4
10
8
6
5
7
9
/RXDA
/CTSA
/DSRA
/TXDA
/RTSA
/DTRA
C5
C7
+5V
C6
+
+
C8
GND
+12VA
–12VA
IC4
RXDB
CTSB
DSRB
MC145407
–
CEXT
+
–
CEXT
+
+10V
–10V
TXDB
RTSB
DTRB
1
+
+
1
3
20
18
11
13
15
16
14
12
17
4
10
8
6
5
7
9
/RXDRS
/CTSB
/DSRB
/TXDB
/RTSB
/DTRB
C9
C11
+5V
C10
+
+
C12
+12VB
–12VB
+5V
/RXDA
/TXDA
/DSRA
/CTSA
/DTRA
/RTSA
/TXDB
/DSRB
/CTSB
/DTRB
/RTSB
3
P3
/RXDCL
/RXDRS
/RXDB
/TXDB
2
1
GND
R7
X1
74AC14
9 8
IC3D
R8
Q1
XINT
+5V
D1
+5.3V
C20
+
P6
+
C21
D3
+5.3V
GND
GND
+5.3VEXT
*
GND
/RTSB
GND