PlantLinc
PLR5000 User’s Guide
P/N 161-09888-001
DATA-LINC
Group
16
Main Menu Option (4): Show Radio Statistics
Option (4) in the main menu allows the user to view data transmission statistics, which have been gathered by
the Transceiver during the most recent session. Statistics are gathered during each data link and are reset
when the next link begins. Ideally, noise levels should be below 30, and the difference between the average
signal level and average noise level should be 30 or more. High noise levels tend to indicate other sources of
RF interference, while low signal levels indicate a weak link. The “Local” stats are the statistics that are being
gathered by the modem you are connected to while “Remote1, Remote2, and Remote3” are the stats of the
Repeater(s) that the modem you are attached to is using to get back to the Master modem. The following
sections provide information useful to the process of troubleshooting and improving radio links.
Average Noise Level
The average noise level indicates the level of background noise and interference at this modem and at each of
the modems used as Repeaters in the link. The number is an average of the noise levels measured at each
frequency in the modems’ frequency hop table. The individual measurement values at each frequency hop
channel are shown in the frequency table. The frequency table is accessed by pressing the ENTER key on the
computer when the radio statistics menu is displayed. Average noise levels will typically fall in the range of
15 to 30. Average noise levels significantly higher than this are an indication of a high level of interference
that may degrade the performance of the link. High noise levels can often be improved with bandpass filters,
antenna placement or antenna polarization. Please contact Data-Linc Group for more information.
Average Signal Level
The average signal level indicates the level of received signal at this modem and at each of the modems used
as Repeaters in the link. For each of these, the signal source is the modem that transmits to it. The number is
an average of the received signal levels measured at each frequency in the modem’s frequency hop table. The
individual measurement values at each frequency hop channel are shown in the frequency table. The
frequency table is accessed by pressing the ENTER key on the computer when the radio statistics menu is
displayed.
For a reliable link, the average signal level should be at least 15 higher than the average noise level reading.
Low Average Signal Levels can often be corrected with higher gain antennas, antenna placement, and use of
Repeaters. Contact Data-Linc Group for more information.
Overall Rcv Rate (%)
The Overall Rcv Rate measures the percentage of data packets that were successfully transmitted from the
Master to the Remote on the first attempt without requiring retransmission. A number of 75 or higher
indicates a robust link that will provide very good performance even at high data transmission rates. A
number of 25 or lower indicates a weak or marginal link that will provide lower data throughput.
