Campbell CRVW3, Инструкция по эксплуатации

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C-1
Appendix C. Aggregating Dataloggers
When you deploy a network of CRVW3 devices using radio telemetry, you
have the option of placing an aggregating datalogger into that network. An
aggregating datalogger is a Campbell Scientific CR300-series, CR6-series,
CR1000, CR3000, or CR800-series datalogger that connects to CRVW3
devices over a radio link and collects data from them. That data is stored on the
datalogger (i.e., aggregated) for later retrieval by LoggerNet software or other
means. For simple radio networks as well as for many other radio network
configurations, an aggregating datalogger may not be necessary.
An aggregating datalogger can also be configured as the base radio station, but
that is not required.
To be a part of the radio network, a radio that is compatible with the CRVW3
radio network must be integrated to the datalogger. This will be an RF450
device, an RF451 device, or an RF407 device. The CR6 is available with the
–RF451 or –RF407 option which will provide a built-in radio option for
connecting to the CRVW3 network. CR300-series dataloggers are also
available with the built-in –RF407 option.
Some of the reasons why you would use an aggregating datalogger are:
•
You use a system other than LoggerNet that can communicate with
the CR300, CR6, CR1000, CR3000, or CR800 devices (ModBus, etc.)
but not the CRVW3 devices
• Sensors other than vibrating-wire sensors need to be measured as part
of the system
•
You want to aggregate the CRVW3 data for backup or redundancy
purposes
• You want to have only one point of contact for data within LoggerNet
(in this case the aggregator is the base station)
If you choose to use an aggregating datalogger, you must include specific kinds
of CRBasic declarations and instructions in the datalogger program that instruct
it to contact the CRVW3 devices and collect their data. This includes the use of
the GetDataRecord() instruction. You should also consider the cost of
purchasing and deploying an additional station.
C.1 Aggregator Station Configuration
You should ensure that proper power, enclosure, grounding, and mounting
options are available for the aggregating datalogger station. If the aggregator
station communicates with more than one remote station (CRVW3 stations,
base station, or other repeaters), it should be configured with an
omnidirectional antenna. If it communicates with only one other station, a
directional/Yagi antenna should be used. If the aggregator station is also the
base radio station, some other medium of communication must be used
between the datalogger and
LoggerNet
(serial cable, TCP/IP, cell modem, etc.).
If no connection to LoggerNet is configured, regular visits to the datalogger to
collect the aggregated data must be made.