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SOI. In the Normal mode and Software Trigger mode, the SOI still marks the beginning of the Single Strobe, but due to the
nondeterministic timing of the software and computer operating system, this timing will change over time and is not periodic. That
is, at a constant integration time, the Single Strobe will not be periodic, but it will indicate the start of the integration.
The Trigger Delay (TD) is another user programmable delay that specifies the time in 500 ns increments that the SOI will be delayed
beyond the normal Start of Integration Delay (SOID).
An example calculation of the Single Strobe timing follows:
If the TD = 1 ms, SSHTD = 50 ms, and SSLTD = 70 ms then, the rising edge of the Single Strobe will occur approximately 51.82 ms (1
ms + 50 ms + 8.2 us) after the External Trigger Input goes high and the Pulse Width will be 20 ms (70 ms
–
50 ms).
Continuous Strobe
The Continuous Strobe signal is a programmable frequency pulse-train with a 50% duty cycle. It is programmed by specifying the
desired period whose range is 2 us to 60 s. This signal is continuous once enabled, but is not synchronized to the Start of Integration
or External Trigger Input. The Continuous Strobe is only active if the Lamp Enable command is active.
Synchronous Continuous Strobe
In Synchronous mode, the strobe will always be the same integer number of pulses per integration period, and deterministic from the
start of integration. Setting the strobe period to greater than the ((integration time/2)-strobe offset) will result in nonguaranteed
behavior (there is no time to do a single pulse).
If the application requires more than one pulse per integration period, ensure the continuous strobe and integration period are
synchronized. The integration time must be set so that an equal number of strobe events occurs during any given integration period.
External Triggering
The Flame Spectrometer has several ways of acquiring data. In the Normal/Free-
Run mode, the spectrometer is “free running.” That
is, the spectrometer is continuously scanning, acquiring, and transferring data to your computer, according to parameters set in the
software. In this mode, there is no way to synchronize the scanning, acquisition, and transfer of data with an external event. However,
trigger pulses for synchronizing an external event with the spectrometer are available.
Each trigger mode involves connecting an external triggering device to the spectrometer and then applying an external trigger to the
spectrometer before the software receives the data. The length of the integration time and the source for the integration clock
depend upon the mode chosen. All other acquisition parameters are set in the software.
Summary of Contents for FLAME
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