USB2-4COMi-M-CBL Hardware Settings and Pinouts

Inside the unit, there are four 4-pin DIP switches used to select the mode of operation. You can switch to RS-232 mode, RS-422 mode or RS-485 mode as per the requirements of your application. After setting the operation mode, you can then proceed to insert the driver CD and start driver installation.

 

RS-232/RS-422/RS-485 Mode Configuration

 

Operation Mode S1 S2 S3 S4
RS-232 Standard RS-232 Mode OFF ON ON ON
RS-422 4 wire with handshaking ON ON ON ON
RS-485 Full duplex (4 wire) ON OFF ON ON
Half duplex (2 wire) with echo ON OFF OFF ON
Half duplex (2 wire) without echo ON OFF OFF OFF

 

Termination & Bias Resistor Configuration

Inside the unit, there are four 3 × 7 (JP1~JP4) header blocks which are jumpered Tx, Rx, CTS 120Ω termination resistors and Tx, Rx 750Ω biasing resistors.

You will need to open up the metal case to set the jumper settings as per the requirements of your application.

 

Jumper Function
1-2 enable
2-3 disable
Tx termination of 120Ω. This jumper should always be populated for RS-485 mode.
4-5 enable
5-6 disable
Pull-up Tx+ to VCC by 750Ω bias resistor. This jumper should be populated for pull-up Tx+.
7-8 enable
8-9 disable
Pull-down Tx- to GND by 750Ω bias resistor. This jumper should be populated for pull-down Tx- .
10-11 enable
11-12 disable
Rx termination of 120Ω. This jumper should always be populated for RS-422 mode.
13-14 enable
14-15 disable
Pull-up Rx+ to VCC by 750Ω bias resistor. This jumper should be populated for pull-up Rx+.
16-17 enable
17-18 disable
Pull-down Rx- to GND by 750Ω bias resistor. This jumper should be populated for pull-down Rx-.
19-20 enable
20-21 disable
CTS termination of 120Ω. This jumper should always be populated for RS-422 mode.

 

RS-232/422/485 DB37 Female Connector Pinouts

 

 

RS-232 DB37 Female Connector Pinouts

 

PIN SIGNAL PIN SIGNAL
1 20
2 DCD (3) 21 DTR (3)
3 GND 22 DSR (3)
4 CTS (3) 23 RTS (3)
5 RxD (3) 24 TxD (3)
6 25 DCD (4)
7 DTR (4) 26 GND
8 DSR (4) 27 CTS (4)
9 RTS (4) 28 RxD (4)
10 TxD (4) 29
11 DCD (2) 30 DTR (2)
12 GND 31 DSR (2)
13 CTS (2) 32 RTS (2)
14 RxD (2) 33 TxD (2)
15 34 DCD (1)
16 DTR (1) 35 GND
17 DSR (1) 36 CTS (1)
18 RTS (1) 37 RxD (1)
19 TxD (1)

 

RS-422 DB37 Female Connector Pinouts

 

PIN SIGNAL PIN SIGNAL
1 20 CTS- (3)
2 TxD- (3) 21 RxD- (3)
3 GND 22 RTS- (3)
4 CTS+ (3) 23 RTS+ (3)
5 TxD+ (3) 24 RxD+ (3)
6 CTS- (4) 25 TxD- (4)
7 RxD- (4) 26 GND
8 RTS- (4) 27 CTS+ (4)
9 RTS+ (4) 28 TxD+ (4)
10 RxD+ (4) 29 CTS-2 (2)
11 TxD- (2) 30 RxD- (2)
12 GND 31 RTS- (2)
13 CTS+ (2) 32 RTS+ (2)
14 TxD+ (2) 33 RxD+ (2)
15 CTS- (1) 34 TxD- (1)
16 RxD- (1) 35 GND
17 RTS- (1) 36 CTS+ (1)
18 RTS+ (1) 37 TxD+ (1)
19 RxD+ (1)

 

RS-485 4-Wire (Full duplex) DB37 Female Connector Pinouts

 

PIN SIGNAL PIN SIGNAL
1 20
2 TxD- (3) 21 RxD- (3)
3 GND 22
4 23
5 TxD+ (3) 24 RxD+ (3)
6 25 TxD- (4)
7 RxD- (4) 26 GND
8 27
9 28 TxD+ (4)
10 RxD+ (4) 29
11 TxD- (2) 30 RxD- (2)
12 GND 31
13 32
14 TxD+ (2) 33 RxD+ (2)
15 34 TxD- (1)
16 RxD- (1) 35 GND
17 36
18 37 TxD+ (1)
19 RxD+ (1)

 

RS-485 2-Wire (Half duplex) DB37 Female Connector Pinouts

 

PIN SIGNAL PIN SIGNAL
1 20
2 Data- (3) 21
3 GND 22
4 23
5 Data+ (3) 24
6 25 Data- (4)
7 26 GND
8 27
9 28 Data+ (4)
10 29
11 Data- (2) 30
12 GND 31
13 32
14 Data+ (2) 33
15 34 Data- (1)
16 35 GND
17 36
18 37 Data+ (1)
19

 

RS-232/422/485 DB9 Male Connector Pinouts

 

 

RS-232 DB9 Male Connector Pinouts

 

PIN SIGNAL
1 DCD
2 RxD
3 TxD
4 DTR
5 GND
6 DSR
7 RTS
8 CTS
9

 

RS-422 DB9 Male Connector Pinouts

 

PIN SIGNAL
1 TxD- (A)
2 TxD+ (B)
3 RxD+ (B)
4 RxD- (A)
5 GND
6 RTS- (A)
7 RTS+ (B)
8 CTS+ (B)
9 CTS- (A)

 

RS-485 4-Wire (Full duplex) DB9 Male Connector Pinouts

 

PIN SIGNAL
1 TxD- (A)
2 TxD+ (B)
3 RxD+ (B)
4 RxD- (A)
5 GND

 

RS-485 2-Wire (Half duplex) DB9 Male Connector Pinouts

 

PIN SIGNAL
1 Data- (A)
2 Data+ (B)
5 GND

 

RS-422/485 Signal Wiring

RS-422

Point-to-Point 4 Wire Full Duplex

 

 

RS-422 with Handshaking

 

 

RS-485

Point-to-Point 4 Wire Full Duplex

 

 

Multidrop RS-485 2-Wire Half-duplex