UBI EasyCoder 501 – Service Manual
157
RS 422/485 Interface Board 1-971708-40
21.5
Circuit Diagram
21. RS 422/485 INTERFACE BOARD, cont'd.
F5
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
74AC14M
5 6
IC3C
/RXDA
/TXDA
/RXDB
/TXDB
/DSRB
JUM1
JUM2
JUM3
JUM4
/CTSB
JUM5
/JUMEN
/DTRB
/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
IC2
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
+5V
C17
C16
GND
3.6864 MHz
P5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
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
/DTRB
JUM3
A4
A3
A2
A1
47k
7
9
10
8
3
6
5
4
2
1
/RXDB
/CTSB
/DSRB
/TXDB
/RTSB
/DTRB
C12
C14
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
+5V
C13
+
+
C15
GND
F6
F8
F10
F7
F11
F12
GNDC
TXDB
RXDB
RTSB
CTSB
DSRB
GNDI
+5VEXT
DTRB
F9
26
27
GNDC
GNDE
5
R2
6
7
8
5
R1
6N136
2
IC4
6
7
8
3
GNDE
5
R3
2
6
7
8
3
+5V
1 2
IC3A & F
/RTSA
R6
2
3
+5V
74AC14M
3 4
IC3B
/RXDA
R5
74AC14M
11 10
IC3E
/TXDA
+5V
R4
VEE
6N136
IC5
6N136
IC6
VEE
VEE
P3
P3
P2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
75176
GNDE
IC7
R
RE
DE
D
1
2
3
4
8
7
6
5
GNDE
VEE
B
A
75176
IC8
1
2
3
4
8
7
6
5
GNDE
VEE
GNDC
GNDC
F1
F2
GNDC
GNDE
GNDC
F3
F4
+RS422I
–RS422I
+RS422O
–RS422O
R16
R15
P11
P10
P3
R13
VEE
R
RE
DE
D
B
A
P8
P9
R14
GNDE
GNDC
R12
R11
R10
R9
+5V
P7
P11
P10
JUM1
JUM2
JUM3
JUM4
JUM5
/JUMEN
1
3
5
7
9
P6
+
C19
D2
+5.3V
R7
X1
74AC14M
9 8
IC3D
R8
Q1
XINT
13 12
74AC14M
D1
+5.3V
C20
+
+5V
C1, 3, 4
GNDC
GNDC
GNDC
GNDC
GNDC
GNDC
GNDC
GNDC
GNDC
REG.
IC10
3
4
1
2
VEE
GNDE
C7
C8
+
5V
-
+
5V
-
U