Communication with an LI-62x2 Analyzer

Many LI-COR instruments have dedicated software to download data to a Windows®, Mac®, or Linux computer. However, the LI-6252 and LI-6262 CO2 analyzers do not. Fortunately, most command-line terminal programs are able to receive data from these analyzers. Below are the steps necessary to download data from the LI-6252 or LI-6262 analyzer, using a free terminal program called Tera Term.

  1. Connect the 1800-04 serial cable that came with the analyzer. This is a 9-pin to 25-pin straight-through cable. Alternatively, you can use a 9-pin to 9-pin straight-through RS-232 cable, along with a 25-pin to 9-pin adapter.
  2. Connect the other end to the computer, if it has a 9-pin serial port. If not, you will need a USB-to-serial adapter with an FTDI chipset. We have seen that some third-party USB adapters do not accurately transmit all the data from the analyzer to the computer. For this reason, we can only guarantee the 6400-27 adapter from LI-COR, but in general Belkin and Keyspan adapters usually work well.
  3. Download the free Tera Term terminal program at https://download.cnet.com/Tera-Term/3000-2094_4-75766675.html.
  4. Open Tera Term. Select the Serial option, and select the COM port that your instrument is connected to – it may already be selected. Click OK.
  6. Click Setup on the top menu, and enable the Serial option. Select Baud rate = 4800, Data = 8 bit, Parity = none, Stop = 2 bit, and Flow control = none. Click OK.
  8. Click File on the top menu, and select Log. This is where your log file will be saved. Select the directory you want and the name of the file. Instead of the default file extension (.log), you can append it with a text file extension (.txt). For the options at the bottom, you’ll want to enable Append and Plain Text, but nothing else. Click Save. Tera Term is now ready to receive data.
  10. Since there are a variety of ways to dump specific data from the LI-6252 or LI-6262, we recommend following the steps that best match the data output needs as listed in the analyzer’s manual. See Section 7.2 in the LI-6252 manual or Section 6.2 of the LI-6262 manual.
  11. You can close out of Tera Term when the transfer is finished. You can then open the file (tab delimited text file) in a text editor such as Notepad or a spreadsheet application such as Microsoft® Excel® to analyze the data.