Campbell Scientific RF500M Radio Modem - Manual (Page 24)

Section 4. Operation of the Radiotelemetry Network
FIGURE 4-3. LoggerNet Connect Screen
4.2 Datalogger Initiated Communications
The datalogger can send collected data to LoggerNet using the SendData
instruction in the datalogger. This method of data collection is referred to as
One Way Data. With scheduled data collection disabled and LoggerNet
running, the RF polling process of the RF500M retrieves data sent from the
datalogger to LoggerNet. Over an RF500M network, One Way Data is the
most efficient method of data collection.
4.2.1 – One Way Data – RF500M network
The One Way Data method of data collection uses the SendData instruction in
a PakBus Datalogger such as the CR800, CR1000, or CR3000 to send data
records to LoggerNet. With standard scheduled data collection, the
LoggerNet server requests specific records from each datalogger on a given
interval. Although this collection process works well over an RF telemetry
network, dialing each RF Remote to request records and collect data from each
datalogger can take a considerable amount of time.
With One Way Data, the datalogger executes an instruction that will check a
specified data table for a new record and send it to LoggerNet without a
request from LoggerNet. Combining One Way Data with the RF500M polling
process can increase the speed and efficiency of data collection on an RF
telemetry network. The time division polling process of the RF500M is used to
get One Way Data records back to LoggerNet.
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