Types Of Cable And Example Connections - Contec COM-2PD(PCI)H User Manual

Types of Cable and Example Connections

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.
TxD+
TxD -
RxD+
RxD -
RTS+
RTS -
CTS+
CTS -
SG
Figure 3.6. Example Connection RTS and CTS to a External Device in Full Duplex
TxD+
TxD -
RxD+
RxD -
SG
Figure 3.7. Example Connection Oneself loop to RTS and CTS in Full Duplex
TxD+
TxD-
SG
Figure 3.8. Example Connection in Half Duplex
CAUTION
If connecting between external devices and this board with faulty wiring, it will become the cause of
failure.
COM-2PD(PCI)H, COM-4PD(PCI)H
TxD+
TxD -
RxD+
RxD -
RTS+
RTS -
CTS+
CTS -
SG
External device
TxD+
TxD -
RxD+
RxD -
SG
External device
TxD+
TxD-
SG
External device
3. External Connection
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