Operating Instructions RF-2000
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7.2.3 Controlling the RF-2000 via CHROMELEON
Important:
Requirements:
• The communications parameters must be correctly set on
the instrument:
Baudrate: 9600
Databits: 7
Parity: None
Stopbits: 1
To enter the parameters, proceed as described in the
previous section.
• The detector must be switched to the remote mode. The
keyboard will then be deactivated. To release the keyboard
lock, simultaneously press the <SHIFT> and <CE> keys for
at least 3 seconds. See the previous section.
After the RF-2000 device driver is correctly activated in the CHROMELEON
Installation Program (usually by Dionex Service), you can control the RF-2000 from
your control panel.
Choose "Command..." from the "Control" menu. Click "Emission" to view the
available commands and variables for the RF-2000. Under "Help", you will see a
description of the currently selected command. If you need further assistance on
specific commands, please press F1 in CHROMELEON to open the CHROMELEON
online Help system. Find the required term via the Index.
Recording Spectra
Spectra cannot be recorded simultaneously with the emission signal. Single spectra
scans are performed instead. During this time, the pump flow should be stopped to
guarantee a stable status in the flow cell of the RF-2000.
The duration of the scans depends on the set scan speed and the scan range. A
scan from 200 to 900 nm with the scan speed "Fast" takes approx. 85 seconds.
The result of a scan is either an emission spectrum or an excitation spectrum. These
spectra are automatically saved in a spectra library. A library by the name RF-
2000.LIB is created in the timebase directory of the local datasource. All RF-2000
spectra are added to this library.
Proceed as follows to scan an emission spectrum:
• Stop the pump flow via the Flow=0 command.
• Then perform the "ScanEmission" command. Depending on when the pump flow
was stopped and when the scan procedure was started, either a background
spectrum or a peak spectrum is saved.
• Perform the analog procedure to determine an optimum excitation value.
Perform the following steps to record a difference spectrum:
• Record a background spectrum as described above.
• Then choose the command "Save Background Spectrum" to save this spectrum
separately in the detector.
• Reset the pump flow to the original value via the command "Flow= ... ". Continue
until the maximum of the peak to detect is reached.
• Stop the pump flow and record a new spectrum.
The two spectra now exist in the RF-2000 spectra library as well as in individual
spectra in two different storage locations within the detector.
• Perform the command "GetSpectraDifference" to receive a difference spectrum.
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