Hardware Setting and Mode Configuration

Outside the unit, there are eight 3-pin DIP switches which are set to select the mode of operation. You will need to set the switch settings to RS-232 mode, or RS-422, or RS-485 mode as per the requirements of your application.

You need to install driver first, prior to hardware installation. After the setting of DIP switches and connecting power cord to the adapter, you then plug the adapter to USB port to start driver installation.

 

The Mode Block Configuration Settings are listed as follows:

SW1 (Port-1), SW2 (Port-2), SW3 (Port-3), SW4 (Port-4),

SW5 (Port-5), SW6 (Port-6), SW7 (Port-7), SW8 (Port-8)

 

Operation  Mode

S1

S2

S3

RS-422

4 wire with Handshaking

ON

ON

ON

RS-485

Full Duplex (4 wire)


OFF

ON

ON

Half Duplex (2 wire)- with Echo


OFF


OFF

ON

Half Duplex (2 wire) - without Echo


OFF


OFF


OFF

 

JP3 (Port-1), JP4 (Port-2), JP5 (Port-3), JP6 (Port-4)

JP7 (Port-5), JP8 (Port-6), JP9 (Port-7), JP10 (Port-8)

for Termination and Biasing Option Configuration

 

Inside the unit, there are eight 2 x 7 (14 pin) header blocks which are jumpered to enable Tx, Rx, CTS 120 Ohm termination resistors and Tx, Rx 750 Ohm BIASing resistor.

You will need to open up the metal case and set the jumper setting for RS-422 mode or RS-485 mode as per the requirements of your application.

Settings are listed as follows:

Jumper Function
1-2 Tx Termination of 120 Ohm. This jumper should always be populated for RS-485 mode.
3-4 Pull-up Tx+ to VCC by 750 Ohm Bias resistor. This jumper should be populated for pull-up Tx+.
5-6 Pull-down Tx- to GND by 750 Ohm Bias resistor. This jumper should be populated for pull-down Tx- .
7-8 Rx Termination of 120 Ohm. This jumper should always be populated for RS-422 mode.
9-10 Pull-up Rx+ to VCC by 750 Ohm Bias resistor. This jumper should be populated for pull-up Rx+
11-12 Pull-down Rx- to GND by 750 Ohm Bias resistor. This jumper should be populated for pull-down Rx- .
13-14 CTS Termination of 120 Ohm. This jumper should always be populated for RS-422 mode.

 

Note : Sometimes, when operating in RS-422 or RS-485, it is necessary to configure termination and biasing of the data transmission lines. Generally this must be done in the cabling, since this depends on the installation of connections. Before applying the option, check your cable specification for proper impedance matching.

 

RS-232/422/485 Pin-outs & Signals Wiring

RS-422 Signal Pin-outs of DB-9 Male

 

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

 

RS-422 Signal Wiring

 

Point-to-Point 4 Wire Full Duplex

 

RS-422 with Handshaking

 

 

RS-485 4-Wire (Full duplex) Signal Pin-outs of DB-9 Male

 

Pin 1 Tx- (A)
Pin 2 Tx+(B)
Pin 3 Rx+(B)
Pin 4 Rx-(A)
Pin 5 GND

 

RS-485 2-Wire (Half duplex) Signal Pin-outs of DB-9 Male

 

Pin 1 Data- (A)
Pin 2 Data+(B)
Pin 5 GND  

 

RS-485 Signal Wiring

 

Point-to-Point 4-Wire Full Duplex

 


Multidrop RS-485 2-Wire Half-duplex