Connecting to the Thermo Fisher dataTaker

Figure 7‑1. The Thermo Fisher dataTaker DT82E Series 4 data logger can record data from the LI-710.

You can log data from the LI-710 to Thermo Fisher dataTaker DT82E and other loggers that support the SDI-12 protocol. This tutorial and program provide the basic steps for accomplishing this. If you want to add the LI-710 to an existing program, the task may be more complicated. Contact Thermo Fisher for assistance.

Requirements for this tutorial

The following items are required to complete this tutorial.

Configuring the logger

Follow these steps to connect the LI-710 to a dataTaker and configure the logger.

  1. Connect the LI-710 cable to the terminals.
  2. Connect the brown wire to a +12 VDC power supply and the black wire to the ground. Connect the blue wire to the 4D terminal.
  3. Figure 7‑2. The LI-710 connects to a 12 VDC power supply (brown), ground (black), and the 4D terminal (blue).
  4. Connect power to the logger to power it on.
  5. Connect an Ethernet cable between the logger and your computer.
  6. You can also connect it to your local network.
  7. Find the IP address that is assigned to the logger.
  8. Press the down arrow key on the keypad two or three times to see the IP address. If no IP address is given, check the cable to be sure it is connected.
  9. Launch the dEX application.
  10. Add the LI-710 and configure the connection.
  11. Click the + button and enter the IP address. Click Add. When connected, the Status pane will show information about the logger. You can also set the name and short name as desired.
  12. Load the example program.
  13. The program (from records all parameters output by the LI-710. To load it, click the three dots and select Load from a File. Select the file (.dxc extension) and then click Apply to Logger to load the program. The program includes a trigger command that is required by the LI-710, as well as instructions for recording the LI-710 output.
  14. Activate the 12 V power supply.
  15. Under Settings > Logger > Power > Channel Expansion Modules, set Power CEM using 12V output to Always. You have to do this any time you change the logger configuration.
  16. After loading the configuration file and activating the power supply, the dataTaker should record all parameters from the LI-710 every thirty minutes. You can customize the configuration to record only the parameters of interest. Be sure to activate the 12 volt power supply after you have applied the changes.

Retrieving logged data

After data are recorded to the logger internal memory, you can copy the data files to your computer. Here's how:

  1. Connect a computer to the logger using the network cable, open dEX software, and select the device to connect.
  2. Click Data Explorer.
  3. Select a date range by entering a start time and stop time, or select all values.
  4. Click Load Schedule Tree and check the box to select all variables or select the variables of interest.
  5. Click Download.
  6. Leave Download as set to .csv to download a text file with comma-separated values.
  7. Select a directory on your computer and save the file.

You can also view a graph of parameters in the dEX application by following the steps above and clicking Draw instead of Download.

The dEX terminal program

The dEX application has a built-in terminal emulator that can be used to read parameters from LI-710. To use it, connect with the logger as described earlier and follow these steps:

  1. From the home screen, click the Command Line Interface button.
  2. In the console, type SDI12SEND 4 "?!" and press Enter.
  3. The LI-710 will reply with its address.
  4. You can query the LI-710 with more commands, some of which are described below.

Get information

  • Command: SDI12SEND 4 "0I!" (the command is SDI12SEND, the number 4 indicates terminal 4D, followed by quotes enclosing the number zero, the capital letter I for information, and an exclamation point.
  • Reply: 4SDI12: 0I!014LI-COR LI-7101.0ET100033 (the command, identifying information for the sensor, including the device address, manufacturer, model, firmware version, and serial number).

Set the address

Use this command if you need to change the address from 1 to 0.

  • Command: SDI12SEND 4 "1A0!"
  • Reply: 4SDI12: 1A0!0 indicating that the address was changed from 1 to 0.

Read current data from a group

  • Command: SDI12SEND 4 "0R0!" (reads data from group 0)
  • Reply: 4SDI12: 0R0!0+0.00+0.02+0.02+1.39+97.55+22.47+48.87+0
  • Command: SDI12SEND 4 "0R1!" (reads data from group 1)
  • Reply: 4SDI12: 1+0.00+0.02+0.02+97.55+22.47+48.87+600+0

Additional settings

Some settings are not relevant to the evapotranspiration measurement, but may be useful to you for record keeping and convenience.

dataTaker name

You can change the name of the dataTaker. Click Settings > Logger > Site Information and enter a Name. Click Apply. The name will be visible on the display.

dataTaker time and date

You can adjust the date, time, and time zone, or set them to match your computer under Settings > Logger > Time and Date.