Connect Tech Blue Heat/PCI PCI Serial Communications - Manual (Page 38)

Blue Heat/PCI User’s Manual, Connect Tech Inc.
Revision 0.11 38
RS-422/485 Cable Wiring
You can wire Blue Heat/PCI RS-422/485, Opto RS-422/485 and Universal Blue Heat/PCI
RS-422/485 adapters in various ways to communicate with RS-422/485 peripherals. This
section describes a few examples of RS-422/485 cabling schemes.
Figure 13 below describes a 4 wire cabling scheme between a port on the Blue Heat/PCI
RS-422/485, Opto, Opto RS-422/485 or Universal Blue Heat/PCI RS-422/485 adapter to a port
on the RS-422/485 peripheral.
Figure 13: RS-422/485 wiring diagram (4 wire)
RTS +
RTS -
CTS +
CTS -
TxD +
TxD -
RxD +
RxD -
RxD + TxD +
RxD - TxD -
RTS -
CTS -
RTS +
CTS +
SR SR
Blue Heat/PCI RS-422/485 adapter
Universal Blue Heat/PCI RS-422/485 adapter
RS-422/485 peripheral
2
3
4
5
6
7
8
9
1
RTS +
RTS -
CTS +
CTS -
TxD +
TxD -
RxD +
RxD -
RxD + TxD +
RxD - TxD -
RTS -
CTS -
RTS +
CTS +
SR SR
Blue Heat/PCI Opto adapter
Blue Heat/PCI Opto RS-422/485 adapter RS-422/485 peripheral
3
4
2
5
6
9
7
8
1
Technical Tip:
The RS-422/485 electrical interface consists of a differential
signaling scheme. You should always connect the signals with
twisted pairs.