XLINK 500/100 Operations & Maintenance Manual page # 111
10.4.
Additional Telemetry Settings
10.4.1.
Max Tx Time
This value dictates how long the system will keep trying to reach the server. If a connection is
not made during this time, the system will give up on the transmission and mark it as failed.
This value should be less than the Scheduled Interval.
10.4.2.
Retransmit
The retransmit setting controls whether or not the station will automatically attempt to
retransmit failed transmissions. Please see the
10.4.3.
Sensor Cutoff Offset and Skip First Missing
Some setups may result in sensor data not being available in time for transmissions. This is
usually the result of a sensor taking a long time to respond. While this scenario is uncommon,
there are several settings that may be used in order to prevent missing data in transmissions:
Skip First Missing
Sensor Cutoff Offset
When Skip First Missing is enabled (it is enabled by default), if the first reading that was slated
for transmissions is missing, the system will skip that reading and go for the next one.
For example, a measurement is scheduled for 12:00, 12:15, 12:30, etc. A transmission is
scheduled for 12:31. With that setup, the system is supposed to include the 12:30 measurement
in the transmission. However, the system does not find that reading in the log. The system has
two options at this point:
Skip the 12:30 reading and use the 12:15 reading as the first one (Skip First Missing is
On)
Put a missing reading marker in the transmission (Skip First Missing is Off)
The most likely cause for a missing reading is the response time of the sensor. If the sensor takes
several minutes to respond, the reading is likely to be missing. However, if the sensor takes a
variable amount of time to respond, sometimes taking less than two minutes, and sometimes
taking more, the system may end up with inconsistent transmission data content. In that case,
disable Skip First Missing, and increase the Sensor Cutoff Offset.
Sensor Cutoff Offset helps prevent missing data in a transmission by specifying how old the
newest measurement in the transmission may be. The default value for the offset is zero.
Let us continue with the example above. With the Sensor Cutoff Offset at 00:01:00, the
transmission scheduled for 12:31:00 will look for the first measurement to have been collected at
12:30:00. If the Sensor Cutoff were 00:05:00, then the system would not try to include any data
collected after 12:26:00, which would cause the system to use the 12:15:00 reading as the first
one.
10.4.4.
Append Options
The "Append Options" add information to the end of the transmitted data. Not all options are
available for all transmission kinds. Not all transmission formats support all the append options.
