User's Manual

SEL-3031 Instruction Manual Date Code 20091009
Performance Monitoring, Testing, and Troubleshooting
Monitoring Radio Performance
5.2
should match to the results of the path study. If the path study numbers do not match
the actual results then either the data entered is incorrect or information about the
locations was omitted. Contact SEL if you cannot get the calculated values to match
the measured values.
RADIO 1 Date: 09/11/2009 Time: 10:54:26
STATION_A Time Source: Internal
RSSI
-46 dBm
AVAILABILITY: From 09/11/2009 10:53:50
Overall
100.00 %
Zone 1 Zone 2 Zone 3 Zone 4 Zone 5
100.00 % 100.00 % 100.00 % 100.00 % 100.00 %
Zone 6 Zone 7 Zone 8 Zone 9 Zone 10
100.00 % 100.00 % 100.00 % 100.00 % 100.00 %
Figure 5.1 Example RAD Command
If you are using directional antennas, verify they have identical orientation—both sides
must be either polarized horizontally or vertically. Typically, a vertically polarized
antenna will give better results than a horizontally polarized antenna. If the location of
the radio antenna is shared with other antennas operating at the same frequency, then
proper spacing and opposite polarization should be used on one set of the antennas,
along with using the SKIP setting. See Section 2: Installation for more information on
antenna installation. Check the aiming of the antenna while updating the RAD
command until you get the strongest signal. This will require two people, where one
person is moving the position of the antenna in small increments, while the other is
monitoring the RSSI. The antenna position must be rotated on both sides to obtain the
highest signal strength. The RSSI must also be reviewed on each radio. The receive
strength on the remote radio will likely be different than the received strength on the
master radio.
The last step to check is the availability of the radio link. The RAD command will give
the overall availability of the radio link. For protection systems the desire is to have a
radio link with 99.99% availability. This overall availability number is a great way of
directly obtaining this number. If you are running M
IRRORED BITS then you can also
use the end devices for the availability number.
To get a good availability reading, issue a RAD C command from Access Level 2. This
will reset all of the availability numbers. Let the radio link run for a couple of days or
longer. The longer period of time, the more accurate the numbers. After a few days
have passed issue the RAD command and view the availability numbers. If the overall
availability number is less than desired then look at the availability numbers per zone.
If all of the zones are down in availability then more adjustment is needed on the
antennas. If a few of the zones are down and the rest are acceptable then go back to the
radio settings and change the SKIP zone setting. Enter the zones, up to six, that you
want to skip with the lowest availability. Issue a RAD C command and let the radio run
for a couple of days.