RS-232
↔
RS-422 INTERFACE CONVERTER
15
4. Ground Strap and Interface Pinouts
Signal grounds (Pins 19, 20, and 37 on the RS-422 interface and Pin 7 on the RS-232 interface) are
connected together, but not connected to chassis ground (Pin 1). However, for applications requiring all
grounds to be at a common reference point, these pins can be connected to chassis ground by installing
a jumper strap across W6 located at the rear of the printed-circuit board between J1 and P1 (refer to
Figures 4-1 and 4-2).
Figure 4-1. The RS-232 Interface.
Figure 4-2. The RS-422 Interface.
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
28
29
30
31
32
33
34
35
36
37
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
SECONDARY TRANSMITTED DATA
DCE TRANSMITTER SIGNAL ELEMENT TIMING
SECONDARY RECEIVED DATA
RECEIVER SIGNAL ELEMENT TIMING
SECONDARY REQUEST TO SEND
DATA TERMINAL READY
SIGNAL QUALITY DETECTOR
RING INDICATOR
DATA SIGNAL RATE SELECTOR
DTE TRANSMITTER SIGNAL ELEMENT TIMING
RECEIVE COMMON
(+B) SEND DATA
(+B) SEND TIMING
(+B) RECEIVE DATA
(+B) REQUEST TO SEND
(+B) RECEIVE TIMING
(+B) CLEAR TO SEND
TERMINAL IN SERVICE
(+B) DATA MODE
(+B) TERMINAL READY
(+B) RECEIVER READY
SELECT STANDBY
SIGNAL QUALITY
NEW SIGNAL
(+B) TERMINAL TIMING
STANDBY/INDICATOR
SEND COMMON
SHIELD
SIGNALING RATE INDICATOR
SEND DATA (-A)
SEND TIMING (-A)
RECEIVE DATA (-A)
REQUEST TO SEND (-A)
RECEIVE TIMING (-A)
CLEAR TO SEND (-A)
LOCAL LOOPBACK
DATA MODE (-A)
TERMINAL READY (-A)
RECEIVER READY (-A)
REMOTE LOOPBACK
INCOMING CALL
SELECT FREQUENCY
TERMINAL TIMING (-A)
TEST MODE
SIGNAL GROUND
PROTECTIVE GROUND
TRANSMITTED DATA
RECEIVED DATA
REQUEST TO SEND
CLEAR TO SEND
DATA SET READY
SIGNAL GROUND/COMMON RETURN
RECEIVED LINE SIGNAL DETECTOR
+ VOLTAGE
-VOLTAGE
SECONDARY RECEIVED LINE SIGNAL
DETECTOR
SECONDARY CLEAR TO SEND
