UBI EasyCoder 501 – Service Manual
155
21. RS 422/485 INTERFACE BOARD, cont'd.
21.2
Straps, cont'd.
Pin
"uart3:"
Remark
s
1
GNDC
Chassis ground
2
TXDB
Transmitted data from printer
3
RXDB
Received data to printer
4
RTSB
RTS from printer
5
CTSB
CTS to printer
6
DSRB
DSR to printer
7
GNDI
Signal ground
8
–
9
–
10
–
11
–
12
–
13
–
14
–
15
–
16
+5VEXT
+ 5V 200 mA, if strap on P6
17
–
18
–
19
–
20
DTRB
DTR permanently high
21
–
22
–
23
–
24
–
25
–
Pin
"uart2:"
Remark
s
1
GNDC
Chassis ground
2
–
3
–
4
–
5
–
6
–
7
GNDE
Interface ground
8
–
9
–
10
–
11
–
12
–
13
–
14
–
15
+RS422 IN
RS 422 only
16
–
17
-RS422 IN
RS 422 only
18
–
19
+RS422 OUT
RS 422/485
20
–
21
-RS422 OUT
RS 422/485
22
–
23
–
24
–
25
–
"uart2:" is a DB25 female connector.
"uart3:" is a DB25 male connector.
The mounting holes are connected to chassis ground.
21.3
Connector Configuration
STRAP:
S1
S2
S3
S4
S5
Address 0
-
-
-
-
-
Address 1
-
-
-
-
X
Address 2
-
-
-
X
-
Address 3
-
-
-
X
X
Address 4
-
-
X
-
-
Address 5
-
-
X
-
X
Address 6
-
-
X
X
-
Address 7
-
-
X
X
X
Address 8
-
X
-
-
-
Address 9
-
X
-
-
X
Address 10
-
X
-
X
-
Address 11
-
X
-
X
X
Address 12
-
X
X
-
-
Address 13
-
X
X
-
X
Address 14
-
X
X
X
-
Address 15
-
X
X
X
X
STRAP:
S1
S2
S3
S4
S5
Address 16
X
-
-
-
-
Address 17
X
-
-
-
X
Address 18
X
-
-
X
-
Address 19
X
-
-
X
X
Address 20
X
-
X
-
-
Address 21
X
-
X
-
X
Address 22
X
-
X
X
-
Address 23
X
-
X
X
X
Address 24
X
X
-
-
-
Address 25
X
X
-
-
X
Address 26
X
X
-
X
-
Address 27
X
X
-
X
X
Address 28
X
X
X
-
-
Address 29
X
X
X
-
X
Address 30
X
X
X
X
-
Address 31
X
X
X
X
X
X=Strap, – = no strap. Address 0 is normally used for the host.
Address Straps (P-7):
