Ver.1.01

COM-2PD-PE

3

- Connecting directly to the port connector

If connecting an external device directly from the connector on

the board, use a CN5-D9F or equivalent connector.

< Pin Assignment >

For TxD, RxD, and RTS, even numbered pins are + and odd

numbered pins are -.

For CTS, even numbered pins are - and odd numbered pins

are +. This is the opposite of the other signals, but is not a

misprint.

The RS-422A/485 interface works based on a differential signal

whereby the signal is carried by the potential difference between

two lines (+ and -).

Using twisted pair cable is recommended to

improve resistance to noise.

Example Connection RTS and CTS to a External Device in

Full Duplex

Example Connection Oneself loop to RTS and CTS in Full

Duplex

Example Connection in Half Duplex

If connecting between external devices and this board with

faulty wiring, it will become the cause of failure.

TxD1+

Transmit Data+

RTS1- Request to Send-

RTS1+

Request to Send+

TxD1-

Transmit Data-

CN1

SG1

Signal Ground

1

2

3

4

5

6

7

8

9

Receive Data-

RxD1-

Receive Data+

RxD1+

Clear to Send+ CTS1+

Clear to Send- CTS1-

TxD2+

Transmit Data+

RTS2- Request to Send-

RTS2+

Request to Send+

TxD2-

Transmit Data-

CN2

SG2

Signal Ground

1

2

3

4

5

6

7

8

9

Receive Data-

RxD2-

Receive Data+

RxD2+

Clear to Send+ CTS2+

Clear to Send- CTS2-

CAUTION

RTS-

RxD-

TxD-

TxD+

RxD+

RTS+

CTS+

CTS-

SG

RTS-

RxD-

TxD-

TxD+

RxD+

RTS+

CTS+

CTS-

SG

External device

External device

RxD-

TxD-

TxD+

RxD+

SG

RxD-

TxD-

TxD+

RxD+

SG

External device

TxD-

TxD+

SG

TxD-

TxD+

SG

CAUTION

External Connection

Types of Cable and Example Connections