February 2, 2016 | by John Goglia | Engineering + Technology, Wind Resource Assessment

data plan Once you understand the basics of how your logger operates, it's easy to choose the right data plan.

The package has arrived, and you're ready to install the Symphonie series data logger and iPackGPS communications module at your project site. But one question remains: which wireless data plan should you choose? Once you understand the basics of how your logger operates, it's easy to make the right decision. This quick guide will help you on your way.



The is a 15-channel data logger that uses email for all remote communications to and from the logger. The logger sends emails containing the collected data to specified recipients on a defined schedule. The logger provides 10-minute averaged data, and the data files are always the same size regardless of how many sensors are connected to the logger. If the user wishes to remotely make a configuration change to the SymphoniePLUS3, an email can be sent to the logger to apply the changes. For SymphoniePLUS3 loggers, the primary driver for choice of wireless plan is the frequency of data delivery (e.g., a weekly vs. a daily delivery schedule).


The 26-channel SymphoniePRO® Data Logger - Wind retains the ability to email data to the user, but the SymphoniePRO data files vary in size depending on the number of active logger channels, choice of statistical averaging interval (1, 2, 5, 10, 60-minute), and the type of data recorded (statistical vs. statistical + 1 Hz sample data). In particular, the option to record 1 Hz sample data for one or more channels generates relatively large amounts of data. SymphoniePRO Desktop Application has a built-in data file size estimator that updates in real-time during the configuration process, enabling users to see the projected file size before deploying the logger.
The SymphoniePRO logger also allows users to remotely interact with the logger using MetLink, which consumes additional bandwidth proportionately with the usage of this feature.


What is Metlink?

SymphoniePRO adds the MetLink protocol, which allows direct connectivity between a logger and a PC over TCP/IP and USB. MetLink can be used to:

  • Retrieve data from the logger
  • Update logger site information, channel configurations, and communication schedules
  • View data in real-time
  • Update firmware on SymphoniePRO data loggers
  • Update firmware on iPackGPS devices

MetLink Connections

SymphoniePRO allows MetLink connections through “logger initiated” and “logger listening” modes. Logger listening connections are initiated by the user at a PC and require the SymphoniePRO logger to have a static IP address. Typically, the wireless provider must assign a static IP to the device plan. For logger-initiated connections, the PC must be located at a reachable IP address (such as a sub-domain like symprodata.mycompany.com). It is possible to allow both types of connection methods (as well as email), which creates a flexible system.


When selecting a wireless plan for SymphoniePRO, consider how the logger will be configured to record data and how you intend to interact with the logger. For example, will you want a static IP address assigned for each logger? For a typical met mast with 12 active channels set for 10 minute averages, the basic WindLinx plan is appropriate (a static IP is included). We recommend using the SymphoniePRO Desktop Application file size estimator and discussing the intended use with your wireless provider when:

  • Using 1 or 5-minute averaging intervals
  • Using 1 Hz sample data collection on one or more channels
  • Routinely retrieving data from the same data logger via redundant methods (e.g., email + automated MetLink Logger Initiated connections)
  • Allowing for multiple clients to download the same data directly from the logger
  • Using more than 12 channels
  • Viewing live data for extended periods of time each day

This information should serve as a starting point to help you understand the drivers of data consumption and connection capabilities. For more about common configuration scenarios, check out the Knowledge Base entry. For additional information about your SymphoniePRO logger, please see the SymphoniePRO manual (“Appendix C”), which has detailed information about possible communication methods. We strongly recommend reading the manual prior to deploying your system.

john goglia
John Goglia

Part of the very fabric that makes up NRG Systems, "John G" has been with the company for over 20 years and currently serves as lead systems engineer within the Technical Services department. John brings not only vast industry experience but also a mix of technical expertise and unrelenting customer focus to every project he gets involved in.

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