Guidelines For Custom Built Cables; Pin-Out Guidelines For Dce Devices; Pin-Out Guidelines For Dte Devices; Cable Selection Guidelines - Computone IntelliServer RAS 2000 PowerRack Hardware Manual

Guidelines for Custom Built Cables

Pin-out Guidelines for DCE Devices

For most modems and other DCE devices, you will want to use the pin-outs
shown in Figure 3-2. Since the PowerRack does not require DSR and RI, you
may omit these signals from your cable.
You can also omit the RTS and CTS signals if you are not using RTS/CTS flow
control. However, we do not recommend doing this since most of the network
configurations in place today require hardware flow control.

Pin-out Guidelines for DTE Devices

The standard cable shown Figure 3-3 supports a device that could use RTS/CTS
flow control. If your device uses different signals for hardware flow control,
adjust your cable accordingly. If you are using XON/XOFF flow control, you
may be able to omit RTS/CTS entirely.
The standard cable connects the Power Rack's CD pin to the device's DTR. This
allows the RAS 2000 PowerRack to log a user off when he turns off his terminal,
for example. You can omit this signal if you don't require this feature.

Cable Selection Guidelines

Consider the following points when selecting a cable:
•
Cable length
• For maximum noise immunity and lowest RF emissions, use a shielded cable
with a 100%-coverage foil shield at the RJ-45 end.
• Conductors in the cable should be 26-28 AWG.
• While there is no particular advantage to using twisted-pair cables with
RS232 installations, they are commonly available and often found in pre-
wired installations. When using twisted pair cable, make sure that it adheres
to the EIA/TIA-568 standard for assigning cable pairs to RJ-45 plug pins, as
shown on the following page:
RAS 2000 PowerRack Hardware Guide
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