Systech Corporation RCS/5000, Руководство по оборудованию

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Installing the Hardware 13
The RCS/5000 does not require the use of all 8 wires. Only pins 3, 4, and 5 are essential.
RTS/CTS and DTR (pins 2, 7, and 8) are only necessary for flow control. Only one ground,
(e.g., pin 3) is necessary. Although the RCS/5000 requires DCD by default, you can change
the serial port setting so that the DCD signal is not required. To change the setting, use the
command
set ignoredcd portnumber no i
where portnumber is the number of the port to be changed. (For more information, see the
ignoredcd command in the Port Server Administrator’s Guide). Thus, a minimal cable as
shown in Figure 2-8, using only RX (pin 5, data in), TX (pin 4, data out), and SG (pin 3,
ground), can be used.
RJ-45 Pin
Number
DB-25 Pin
Number/Signal
1 DCD
8 DTR
7 CTS
6 SG
5 RXD
4 TXD
3 SG
2 RTS
7 SG
3 RXD
2 TXD
Figure 2-8 RJ-45 to DB-25 3-Wire Terminal Cable
RJ-45 to DB-25 or DB-9 adapters may be used with RJ-45 cables to create the cable
configurations shown in Figures 2-4 through 2-5. In most cases, you use “straight through”
RJ-45 cables. If you use “crossover” RJ-45 cables, the RJ-45 pins will be reversed. Figures 2-9
and 2-10 illustrate the difference between the two types, when constructed with flat 8-
conductor wire.
pin 1
Figure 2-9 RJ-45 to RJ-45 Straight-through Cable