A.4 rs-232 cable db-25 to db-9 translation, A.5 rs-422 cable wiring, Appendix – American Magnetics 135 & 136 Liquid Helium Level Instruments (CE-Marked) User Manual
Page 70: Rev. 3
58
Rev. 3
Appendix
RS-232 Cable DB-25 to DB-9 Translation
A.4 RS-232 Cable DB-25 to DB-9 Translation
All other pins on the DB-25 connector are unused. This is standard PC
modem cable wiring.
A.5 RS-422 Cable Wiring
DB-25 Pin
DB-9 Pin
2
3
3
2
4
7
5
8
6
6
7
5
8
1
20
4
22
9
13X/18X
INSTRUMENT
EIA-530
DEVICE
13X/18X CONNECTOR
EIA-530 CONNECTOR
RX+ (PIN 2)
TX+ (PIN 14)
TX+ (PIN 3)
TX- (PIN16)
RX- (PIN 21)
TWISTED PAIR
TWISTED PAIR
<TWISTED PAIR>
TX- (PIN 2)
RX+ (PIN 16)
RX- (PIN 3)
<TWISTED PAIR>
RX+
RX-
TX-
TX+
EARTH GROUND
(SHOWN FOR
REFERENCE ONLY;
CONNECTED TO
INSTRUMENT
CHASSIS AND TO
AC MAINS "EARTH"
CONDUCTOR)
SIGNAL GROUND
(SHOWN FOR
REFERENCE ONLY;
CONNECTED TO
INSTRUMENT RS-422
DRIVER/RECEIVER
CIRCUIT GROUND)
DB25 FEMALE
13
25
12
24
11
23
10
22
9
21
8
20
7
19
6
18
5
17
4
16
3
15
2
14
1
DB25 MALE
13
25
12
24
11
23
10
22
9
21
8
20
7
19
6
18
5
17
4
16
3
15
2
14
1