Ver.1.00

COM-4DL-PCI

3

The figures below show examples of how to connect the cable for the board.

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

RTS-

RxD-

TxD-

TxD+

RxD+

RTS+

CTS+

CTS-

SG

RTS-

RxD-

TxD-

TxD+

RxD+

RTS+

CTS+

CTS-

SG

External device

Example Connection RTS and CTS to a External Device in Full Duplex

External device

RxD

-

TxD

-

TxD+

RxD+

SG

RxD

-

TxD

-

TxD+

RxD+

SG

Example Connection in Half Duplex

External device

TxD-

TxD+

SG

TxD-

TxD+

SG

CAUTION

If you are connecting between external devices and this board with faulty wiring, it will become the cause of failure.

Types of Cables and Connection Examples