EOL Zenith Data Logger

What format should the SD memory have for it to work with the EOL Zenith?

If you are using the SD memory card that was supplied together with the data logger, the SD card is already formatted.

In case you want to re-format a SD card please follow these steps:

1.       Turn off the data logger

2.       Insert the SD card you want to format into the data logger

3.       Turn the data logger on

4.       Wait for at least 12 minutes

The SD card is now formatted correctly.

Can I use another SD memory card with the data logger?

Yes, you can use other SD memory cards (with a maximum capacity of 2GB). Please make sure that the SD card is correctly formatted before use.

Not all SD memory cards are the same. We strongly recommend using the SD memory card that was supplied together with the data logger since these SD memory cards are industrial grade cards.

How does the data management system work for the EOL Zenith?

Before you get started with EOL Manager and the EOL Zenith data logger read this.

The EOL Manager is used to prepare the configuration file for the EOL Zenith data logger. The .sit file (configuration file) is then uploaded to the data logger.

EOL Manager downloads the encrypted .log file from the data logger. The .log file contains all the RAW data (the pulses and Hz stored from all the sensors connected to the data logger)

EOL Manager then automatically converts the .log file into a .wnd file and .txt file using the active logger configuration file (also stored on your PC)

I need a SIM card that enables internet connection to my EOL Zenith data logger. Where can I get it?

Our engineers have come up with a solution for a single SIM card that offers Internet connection to your data loggers and works in almost all countries worldwide. A single SIM card that checks for all available local GPRS signals and automatically connects to the one with the best coverage.

Benefits with our new Global SIM card:

  • Internet connection to all your data loggers
  • Faster download times
  • One solution for all your sites
  • Get the most out of EOL Manager including automatic data transfers
  • No more talking to your local GSM provider
  • Cost effective and no monthly data plans 

Click here for more information on our “Global SIM Card”

Contact us on for more information and prices on this Global Internet SIM card.

What battery should I use for the data logger?

We recommend using a flotation (back-up) sealed lead-acid battery (12VDC). This kind of battery has no maintenance and can be transported in any orientation. If you are performing wind measurement and are using an internet / GSM connection to your data logger, we recommend using a 24Ah battery. This gives autonomy of approximately 1 month without the battery being recharged.

How do I make sure my solar panel is charging the battery correctly?

To test that the solar power supply system has been installed and performs properly you need a multimeter set to “Read Current” mode.

Step 1

To begin with you should check if the output from the solar panel is correct. You should do this on a sunny day (Please connect the multimeter as shown in drawing here below)

Step 2

Now check that the regulator is charging the battery. There are leds on the solar regulator helping you to indicate if the regulator is charging the battery. But to be sure you should check with the multimeter (see drawing here below)

In addition to dimensioning the solar power supply system correctly, it is important to orient the solar panels appropriately for maximum electricity production. See FAQ "How should I install the solar panel for charging the battery"

How should I connect the power supply to the EOL Zenith data logger?

Usually solar power systems for the EOL Zenith consist of a solar panel, a charge controller and a battery.


Always connect the battery terminals directly to the BAT + and – on the data logger. Do not connect the LOAD+ and LOAD- to the data logger. The reason we recommend this is to avoid the regulator to switch off its outputs when the battery drops below a certain cutoff limit for the regulator. Keep in mind that the data logger can work with 5V.

See figure 1.2A

The solar power supply system must be dimensioned depending on the location of the measurement site and the number of sensors connected to the data logger. 

An example: A met mast installation with the following sensors connected to the data logger equipped with a 20W solar panel and a 40Ah battery would give you approximately 45 days of complete autonomy (Location Germany).

  • 6 Anemometers
  • 2 Wind vanes
  • 1 Temperature & Humidity 
  • 1 Pressure sensor

How do I setup the EOL Zenith in the beginning?

We have created a "Quick User Guide" for new users. It is a quick way to get started and explains some of the general working of the data management system. Click here to download it.

Where is the data stored on the data logger?

The RAW data is stored on the SD card inserted in the data logger. All the RAW data is encrypted and can only be extracted using EOL Manager. You cannot use Windows Explorer to extract data from the SD memory card.

How to ground the data logger correctly.

To ground the EOL Zenith®, connect one end of the copper ground wire (usually yellow-green color) to the data logger GND terminal and the other end to an independent grounding spike.

If the enclosure is metallic you must also connect the enclosure to the ground wire, to do so, all metallic enclosures have a connection screw terminal with the ground symbol on it.

Click here to download our "how to ground" guide

How should I install the solar panel for charging the battery?

In addition to dimensioning the solar power supply system correctly, it is important to orientate the solar panels appropriately for maximizing the energy production during the season with less sun energy.

In general the solar panel should be facing GEOGRAPHICAL SOUTH in the Northern hemisphere and GEOGRAPHICAL NORTH in the Southern hemisphere. And as a rule of thumb the inclination of the solar panel should be the latitude of the site where you are installing the solar panel -10°.

E.g. For an installation in Germany, close to Frankfurt (with latitude 50° N) you should orientate the solar panel towards SOUTH and with an inclination of 40° with respect to horizontal.

For sites in the North (e.g. Scandinavia), or where there may be very little sunlight during certain periods of the year, an individual solar radiation calculation should be carried out. You can contact our technical support for help on this.

Tropical and Equatorial sites

In inter-tropical latitudes the sun can be located either North or South. In the equator, for example, the met mast structure shadow is projected to the South for 6 months and to the North for the other 6 months. This of course lowers the radiation on the solar panel and we therefore recommend installing two separate solar panels.

Installing two solar panels

If you are going to install two separate solar panels, we recommend the following configuration (see images below). Both panels are to be installed in booms parallels to the West-East Earth axis, with one solar panel pointed towards the North (and tilted approx. 10°) and the other one pointed towards the South (and tilted approx. 10°). The charging efficiency is increased by using independent solar chargers for each solar panel.


EOL Manager

How to download and install EOL Manager

Log into your account with you username and password. From the download menu within your account you can download the latest version of EOL Manager.

When you have downloaded the installation file (EOLManagerSetup.msi) locate the file on your PC and double click it. One single file (EOLManagerSetup.msi) installs both the EOL Manager® and EOL Charting on your pc.

The first time you run the software, it will ask for the folder you wish all the data files to be located. That folder will contain all other folders associated with all your future wind measurement sites.

We encourage you to keep up to date with the latest EOL Manager version. When you update to a newer version of EOL Manager, please uninstall the “old” version first and then reinstall the new version. No data and/or configuration files are lost during this uninstall and reinstall process.

System requirements:

Operating System: EOL Manager is supported on Windows 7, Windows 8 and Windows XP with .NET Framework version 3.5 SP3 or later version installed.

MMC card reader: You need a MMC card reader for accessing the data on the MMC card from your PC as well as for configuring the EOL Zenith with your logger settings.

Google Earth: If you want to see the exact position of your wind measurement sites, you need to install Google Earth on your PC.

Telephone connection or Internet access: If you are planning to connect to the data logger via a telephone MODEM or Internet. We strongly recommend connecting to your data logger via your internet connection.

How do I get and/or renew my EOL Manager license?

The EOL Manager software needs an active license to run on your computer. You can get and/or renew your software license directly from your online user account.

If you do not already have a license, go to "Request Account" and fill out the form. Our support team will then upload your first software license to your user account. Once our support team have uploaded your license you will receive an automatic email notification.

When your license is about to expire, just click the “Renew License” button under “Software Licenses” from your user account.

Go to EOL Manager > Options > License Information and insert your software license. (See A)

What is the easiest way to access my latest wind data?

When data is downloaded from your data logger it is automatically stored in the folder you chose when you installed EOL Manager.

The easiest way for you to see your latest data is to right click on your data logger in the main dashboard of EOL Manager. You will then see the menu (as shown here below) where you have access to most of the main features to operate an EOL Zenith data logger.

Click on “Last Data” (See A) to see your data in table format or click “Last Data Charts” to see your data in EOL Charting.

Where should I insert the calibration values from the Measnet calibration certificate?

Open EOL Manager and go to the data logger you are working on. Open the “inputs” tab and type in the calibration values from the Measnet calibration certificate.

Please notice that it is not necessary to upload these calibration values to the data logger. The data logger simply does not use them. All the calibration values are applied by the EOL Manager once the RAW data (.log file) has been downloaded. When connected in real-time to a data logger, the calibration values from the EOL Manager is used. 

What is the most proper way to organize and move wind data files when working with EOL Manager?

Every logger on EOL Manager has its own directory where data is stored. If you want to move the content of the current directory to a new folder, it is very important to do it from EOL Manager and not from Windows. To do so, access to Logger SettingsSite Info tab → Download Directory and type in the User Defined Path field, the path of the new folder you want to move the wind data files to. In case the selected folder does not exist, EOL Manager will create it automatically and then it will automatically move the content from the old directory to the new one. Future data downloaded will be stored in that new path as well.

How can I extract the data from an .elog file?

The .elog files contain raw data that were sent by email, either by the logger itself or by another EOL Manager forwarding them after download. You can configure EOL Manager to extract the data from the .elog files automatically by selecting “Read Emails From Logger / Synchronize from other EOL Manager” in the “Download” tab of the Logger Settings. In case you need to do it manually, go to Tools --> Import Data Downloaded By Email and then select the files you want to extract the data from. Decoding an .elog file generates three new files: .log (raw data), .txt (report) and .wnd (decoded data).

How can I automatically share data with others?

There are several ways to share data from the EOL Zenith data logger with e.g. your colleagues, external consultants or your met mast installation company. Click here to download our guide.


What add on modules exist for the EOL Zenith?

There are currently 4 add on modules for the EOL Zenith data logger.

  1. Ultrasonic module for connecting ultrasonic sensors directly to the data logger
  2. Windfarm module for connecting the data logger via Modbus to SCADA
  3. Satellite module for sites without GSM coverage
  4. 1 sec. data storage module for original 1 Hz data from your sensors

We will update this list when new modules are ready.

What options do your offer for satellite communication?

The Satellite Module provides coverage in remote areas without access to the regular GSM network. It was designed for use with the Iridium constellation however also extended to cover the Inmarsat (BGAN) system. The satellite module includes a preinstalled satellite modem, satellite antenna and all the wiring needed.

The intelligent data compression in the EOL Zenith significantly lowers the time for satellite communication and thereby also lowers the costs for transferring data (compared to other non-compressed methods).

Click here to read more about the “Satellite Communication Module


What sensors are compatible with the EOL Zenith?

All the most common sensors (anemometers, wind vanes, etc.) used in wind & solar resource assessment are compatible with the EOL Zenith.

Click here to download the list of sensors compatible with the EOL Zenith.

If you have a specific sensor you want to connect to the EOL Zenith which is not already on this list, feel free to contact our technical support.

We plan to install a barometer at the top of the met mast (e.g. 80 meter). What do we need to take into account?

This depends on the type of barometer. If you use the e.g. Setra M276 sensor (output in voltage) you need to increase the cable section from 0,5mm2 to 2.5 mm2 to avoid signal loss.

Unlike most other barometers the frequency output from the K611P barometer however ensures signal integrity from the top of the met mast all the way down to the data logger at the bottom. You do therefore not need to increase the cable section when using this sensor. The K611P barometer is therefore, in most cases, the most cost effective overall solution (saving you costs on cable).

Solar Resource Assessment

Can I connect a (thermopile) pyranometer directly to the EOL Zenith data logger?

Not directly. The output signal from this pyranometer is in milivolts and the input channels on the EOL Zenith ranges from 0-5 volts. You therefore need an amplifyer for this pyranometer. The amplifyer we supply is called AMPVAR. 

Why is there a negative output during nighttime solar measurements?

This error is related to the zero offset type A. Normally this zero offset is present when the inner dome has a different temperature from the cold junctions of the sensor. Practically this is always the case when there is a clear sky. Because of the low effective sky temperature (<0 °C) the earth surface emits roughly 100 W/m2 longwave infrared radiation upwards. The outer glass dome of a pyranometer also has this emission and is cooling down several degrees below air temperature (the emissivity of glass for the particular wavelength region is nearly. The emitted heat is attracted from the body (by conduction in the dome), from the air (by wind) and from the inner dome (through infrared radiation). The inner dome is cooling down too and will attract heat from the body by conduction and from the sensor by the net infrared radiation. The latter heat flow is opposite to the heat flow from absorbed solar radiation and causes the well known zero depression at night. This negative zero offset is also present on a clear day, however, hidden in the solar radiation signal.

Zero offset type A can be checked by placing a light and IR reflecting cap over the pyranometer. The response to solar radiation will decay with a time constant (1/e) of 1 s, but the dome temperature will go to equilibrium with a time constant of several minutes. So after half a minute the remaining signal represents mainly zero offset type A.

Good ventilation of domes and body is the solution to reducing zero offsets even further.


What is Sodar?

Sodar stands for Sonic Detection And Ranging. It works by sending out a sound pulse and recording the reflections scattered back off the atmosphere. The change is sound frequency of the reflection is converted into wind conditions and the time it takes to detect the returned sound indicates the height of the measurement.

What data do you get from a Fulcrum3D Sodar?

The Fulcrum3D Sodar provides data on wind conditions including wind speed, wind direction, wind speed standard deviation and inflow angle (related to vertical wind speed).

How is the Fulcrum3D different from other remote sensing?

The Fulcrum3D Sodar is different to most Sodar devices available on the market. The main features are listed below:
- Specifically designed for use in complex terrain. - Accurate and highly validated by independent consultants. - Fixed beam angles for greater consistency between sites. - Full raw data capture allows historic data to be reprocessed with updated firmware. - Fully integrated power supply and communications included in price.

What is the track record of the Fulcrum3D Sodar?

The unit has been used in a variety of deployments over four continents ranging from two week verifications to multiyear campaigns. These have covered both simple and complex terrain, operations between -10º to 50ºC and in both dessert and tropical locations.


How is the wind vane’s offset obtained at night or when the weather is cloudy?

In the abscense of sunlight, the Geovane will keep the latest valid data obtained since it was powered on. As soon as it receives sufficient radiation from the Sun, Geovane will update its orientation output. This temporary “pause” does not imply any inconvenience due to the nature of the data.

Does the Geovane provide an offset figure or is it mechanically adjusting the unit it is installed on (e.g. the wind vane)?

Assuming that the Geovane has been properly aligned with the wind vane by means of its built-in laser, the Geovane will then continuously provide the angular wind vane offset with respect to Geographic North. The user should then apply this offset in the post processing of the dataset.

Can I use the Geovane with any data logger?

Yes, the Geovane is fully compatible with any industry standard data logger through the following output options:

  • Frequency ouput 30-130Hz (0-5V square wave)
  • Analog output 0.5-4.5V
  • RS-485 digital ouput

What wind vanes are compatible with the Geovane?

At the moment, the wind vanes compatible with Geovane are: Thies First Class, Thies Compact, Young Wind Monitor, Young Wind Monitor Alpine, Vector W200P, NRG 200P and Ornytion 207P. In the future, it will be possible to extend compatibilty even further.

What is the geovane_turbine application?

The Geovane_turbine application offers the exact orientation of the turbine’s nacelle with respect to True North. Aligning all your wind turbines to the same angular reference point enables the wind farm operator to compare yaw turbine alignments.
This means that all the turbine yaw encoders in any given windfarm now have the same reference point.
The Geovane_turbine application is specifically developed for turbine alignment and includes ad hoc hardware and software. It is used as a portable instrument, carried by the O&M team from one wind turbine to another offering once-in-lifetime corrections per turbine.

What is the geovane_metmast_verification application?

By adding a new wind vane equipped with a Geovane to an already existing met mast, you are able to correct existing wind direction datasets whitout altering the consistency of previous wind vane measurements.

What are the advantages of installing a Geovane from the beginning of a wind measurement campaign?

If the Geovane is installed from the beginning, it is possible to have wind direction datasets inmune to the torsion of the tower structure or bended sensor booms. Throughout the measurement campaign, the Geovane will provide the updated offset, achieving absolute accuracy and greater guarantees to external auditors and financial investors.

Is there any preferred orientation or recommended position when installing a Geovane onto the sensor boom?

No. Any orientation can be used, since the azimuthal Field of View (FOV) of the Geovane is 360°. The Geovane should obviously be perfectly aligned with the e.g. wind vane (see the user manual how to do this).
It is recommended that the wind vane’s cable is positioned in such a way, that it runs down the side of the Geovane facing the nearest Earth’s pole or the met mast itself. This is to reduce the shadow projection caused by the cable, but this is not critical.

What are the advantages of using RS-485 digital communication over analog ouputs?

In addition to the advantages associated with digital communication and EMI immunity, RS-485 digital output allows the Geovane to provide other useful data apart from the orientation offset: tilt of the sensor, boom vibration, GPS coordinates, UTC time...
A Geovane connected via RS-485 can be used as the GPS module for data loggers and RSD without GPS by default.