Black Box RS-422, RS0232 manual Ground Strap and Interface Pinouts, RS-232 Interface

RS-232↔RS-422 INTERFACE CONVERTER

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).

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

14	1	PROTECTIVE GROUND
	2	TRANSMITTED DATA
15
	3	RECEIVED DATA
16
	4	REQUEST TO SEND
17
	5	CLEAR TO SEND
18	6	DATA SET READY
19	7	SIGNAL GROUND/COMMON RETURN
20		RECEIVED LINE SIGNAL DETECTOR
21	8	+ VOLTAGE
22	9	-VOLTAGE
	10
23
	11	SECONDARY RECEIVED LINE SIGNAL
24
	12	DETECTOR
25
	13	SECONDARY CLEAR TO SEND

Figure 4-1. The RS-232 Interface.

RECEIVE COMMON	20			1	SHIELD
				2	SIGNALING RATE INDICATOR
	21
(+B) SEND DATA		3
	22
				4	SEND DATA (-A)
(+B) SEND TIMING	23
				5	SEND TIMING (-A)
(+B) RECEIVE DATA	24
				6	RECEIVE DATA (-A)
(+B) REQUEST TO SEND	25
				7	REQUEST TO SEND (-A)
(+B) RECEIVE TIMING	26
				8	RECEIVE TIMING (-A)
(+B) CLEAR TO SEND	27
				9	CLEAR TO SEND (-A)
TERMINAL IN SERVICE	28
			10		LOCAL LOOPBACK
(+B) DATA MODE	29
			11 DATA MODE (-A)
(+B) TERMINAL READY	30
			12		TERMINAL READY (-A)
(+B) RECEIVER READY	31
			13		RECEIVER READY (-A)
SELECT STANDBY	32
			14		REMOTE LOOPBACK
SIGNAL QUALITY	33
			15		INCOMING CALL
NEW SIGNAL	34
			16		SELECT FREQUENCY
(+B) TERMINAL TIMING	35
			17		TERMINAL TIMING (-A)
STANDBY/INDICATOR	36
			18		TEST MODE
SEND COMMON	37
			19		SIGNAL GROUND

Figure 4-2. The RS-422 Interface.

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