Environmental
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New OPEN 5.3 Software Now Available
LI-COR continues to maintain the LI-6400 as the state-of-the-art photosynthesis system with updates to instrument and computer interface software. Released in July of 2005, OPEN 5.3 software offers two new exciting features for LI-6400 users.
Multi-Level Flash Option for the 6400-40 Leaf Chamber Fluorometer
For users of the 6400-40 Leaf Chamber Fluorometer, OPEN 5.3 enables a multi-intensity flash option for the saturating pulse.
Assessing Fv in either light- or dark-adapted measurements requires application of a saturating flash of light to fully reduce QA, the primary acceptor of PSII. It is known that some field-grown, light-adapted leaves are especially difficult to saturate, even with 20,000 μmol photons m-2 s-1 PPFD. An alternative solution exists to estimate the true Fm' under non-saturating conditions, which was introduced by Markgraf and Berry in 1990(1), and more recently by Earl and Ennahli in 2004(2).
With Version 5.3 OPEN software, the LI-6400/6400-40 System supports two types of saturating flashes; single or multiple intensity. A single intensity flash provides a saturating pulse of light for a short duration, and the software looks for the maximum value of fluorescence during that pulse. The multiple intensity flash method applies three intensities within a single flash of 1.5 to 2 s in length. Flash intensities and length are user-defined. After the multiple intensity flash is applied, the software computes the fluorescence at saturation from the y-intercept of a plot of fluorescence vs. 1/ intensity. Earl and Ennahli’s(3) method separates the saturating flashes of different intensities by minutes, and does not apply them within a single flash. This new multiple intensity flash method is currently under scientific evaluation. To determine if this technique is right for your plant material, we recommend you compare the results of this method to that of Earl and Ennahli’s. If there is no difference, then this method should be appropriate.
Remote Control Capability via the Internet
Version 5.3 adds remote control capability, using a computer connected to the LI-6400 RS-232 port, or over the Internet. The local component of this remote capability is named LTerm, and the Internet component is named iTerm. This powerful new method for remote control of the LI-6400 enables the instrument to be controlled, and its display viewed, from a remote computer while the LI-6400 continues to operate normally. This allows our technical support staff to take control of a user's instrument to diagnose many problems remotely.
LI-6400 software now extends this control to users around the world via the Internet, using a special server (li6400.licor.com), allowing information to pass back and forth between the local and remote computers. The remote Internet connection requires no knowledge of network configuration parameters, and is completely firewall transparent. The local computer passes information to and from the LI-6400, and from there to the Internet and remote computer.
How to get OPEN 5.3
OPEN 5.3 software comes standard with all new LI-6400s, and runs only on the new digital board. LI-6400 users with serial numbers PSC-1214 and above have this digital board and may download OPEN 5.3 software here. Both the instrument software and computer software should be updated to version 5.3.
A field-installable Digital Board and Software Upgrade (p/n 6400-915) is available for instruments with serial numbers below PSC-1214. This package includes the digital board, software, instruction manuals, and installation instructions. Click here for a brochure discussing this upgrade.
A special pricing package is available for the Leaf Chamber Fluorometer and the new digital board/software upgrade. The 6400-40DB package includes the 6400-40 Leaf Chamber Fluorometer, 6400-915 Digital Board and Software Upgrade, spare parts kit, instruction manual, and installation instructions.
(1) Markgraf, T. and J. Berry. 1990. Measurement of photochemical and non-photochemical quenching: correction for turnover of PS2 during steady-state photosynthesis. Curr. Res. Photosynth. 4:279-282.
(2) Earl, H.J. and S. Ennahli. 2004. Estimating photosynthesis electron transport via chlorophyll fluorometry without photosystem II light saturation. Photosynth. Res. 82:177-186.
