3. External Connection
COM-2PD(PCI)H, COM-4PD(PCI)H
37
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.
RTS
-
RxD
-
TxD
-
TxD+
RxD+
RTS+
CTS+
CTS-
SG
RTS
-
RxD
-
TxD
-
TxD+
RxD+
RTS+
CTS+
CTS-
SG
External device
Figure 3.6. Example Connection RTS and CTS to a External Device in Full Duplex
External device
RxD
-
TxD
-
TxD+
RxD+
SG
RxD-
TxD
-
TxD+
RxD+
SG
Figure 3.7. Example Connection Oneself loop to RTS and CTS in Full Duplex
External device
TxD-
TxD+
SG
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.
Summary of Contents for COM-2DL-PCI
Page 7: ...vi COM 2PD PCI H COM 4PD PCI H...
Page 15: ...1 Before Using the Product 8 COM 2PD PCI H COM 4PD PCI H...
Page 39: ...2 Setup 32 COM 2PD PCI H COM 4PD PCI H...
Page 45: ...3 External Connection 38 COM 2PD PCI H COM 4PD PCI H...
Page 55: ...5 About Software 48 COM 2PD PCI H COM 4PD PCI H...