RUGGEDCOM RS930L
Installation Guide
Chapter 3
Communication Ports
Configuration and Setup
15
• Twisted-pairs are an effective way of reducing both magnetic and capacitive interference because they reduce
the magnetic loop area to nearly zero and maintain a consistent distribution of capacitances to both ground and
other sources. Therefore, make sure twisting is consistent throughout cable length.
• Open leads (also known as bridged taps or drop-lines) along the length of the cable will cause an impedance
mismatch and result in VDSL signal degradation.
• Make sure the cable impedance is consistent throughout the run. Avoid mixing different wiring (e.g. wiring
with different gages) in cable runs, as this will cause an impedance mismatch and result in VDSL signal
degradation.
• Make sure wiring is adequately separated between power and control circuits. Switching spikes and surges in
power and control circuits can couple noise onto the VDSL line, causing interruptions in communications.
• Lower speeds are less susceptible to interference and will transmit greater distances over the same wiring than
higher speeds. Use the minimum speed that will provide adequate data transfer speed.
Section 3.1.2
Configuration and Setup
If the RS930L and another device both have Universal EoVDSL ports, configure one device to be the Master
and the other the Slave. If both devices have a Long-Reach EoVDSL port, no Master/Slave configuration is
necessary, since the ports will already be fixed as Master or Slave. Once configured and connected together,
each device will attempt to achieve the maximum speed based on the line length and conditions. The device's
link LED may flash on and off several times before setting on a final link speed and declaring the port up. For
more information about configuring the RS930L, refer to the
ROS User Guide for RS900LW/RS930LW
.
Section 3.1.3
EoVDSL Performance
The EoVDSL ports can be configured to operate in one of two modes: Auto Mode (default) and Manual Mode. In
Auto Mode, the device will step through the different speeds and automatically select the best bit-rate based on
the current line conditions. In Manual Mode, the user can select one of the speed settings and the device will only
attempt to attain the set speed. If the line conditions degrade (reducing the SNR or Signal to Noise Ratio), but the
device is able to maintain the link, an alarm will be triggered to notify the user of the reduced SNR. By configuring
the
Rescan Mode
parameter in ROS, the user can control at which point the scan process will be restarted
when the line conditions degrade. If
Link only
is selected, the device will restart the scan process if the line
conditions degrade such that the device is unable to maintain the current link. If
Link or SNR
is selected, the
device will restart the scan process if either the SNR has dropped below a pre-defined acceptable level or when
the device is unable to maintain the current link, or whichever comes first. Note that if
Mode
is set to
Manual
Mode
, the restart of the scan process will only attempt to attain the set speed in Manual Mode.
For information about configuring EoVDSL, refer to the
RUGGEDCOM ROS for the RS930L
.
NOTE
• EoVDSL ports are designed to be used on private communications lines for point-to-point
connections and are not to be connected to the Public Switched Telephone Network (PSTN).
• To reduce the risk of fire, use only No. 26 AWG or larger telecommunication line cord.
• In Manual Mode, assuming the distance can support the speed setting, the time to port up is typically
15-30 seconds.
