Chapter 5 Timing Modes; Fast And Safe Speed Modes - Princeton Instruments Activity Tracker User Manual

Timing Modes
The Princeton Instruments MicroMAX system has been designed to allow the greatest
possible flexibility when synchronizing data collection with an experiment.
The chart below lists the timing mode combinations. Use this chart in combination with
the detailed descriptions in this chapter to determine the optimal timing configuration.

Fast and Safe Speed Modes

The WinSpec/32 Experiment Setup Timing tab page allows the user to choose Fast or
Safe Mode. Figure 15 is a flowchart comparing the two modes. In Fast Mode operation,
the MicroMAX runs according to the timing of the experiment, with no interruptions from the
computer. In Safe Mode operation, the computer processes each frame as it is received. The
MicroMAX cannot collect the next frame until the previous frame has been completely
processed.
Fast Mode operation is primarily for collecting "real-time" sequences of experimental
data, where timing is critical and events cannot be missed. Once the MicroMAX is sent
the Start Acquisition command (STARTACQ) by the computer, all frames are collected
without further intervention from the computer. The advantage of this timing mode is
that timing is controlled completely through hardware. A drawback to this mode is that
the computer will only display frames when it is not performing other tasks. Image
display has a lower priority, so the image on the screen may lag several images behind.
A video monitor connected to the VIDEO output will always display the current image.
A second drawback is that a data overrun may occur if the number of images collected
exceeds the amount of allocated RAM or if the computer cannot keep up with the data
rate.
Safe Mode operation is primarily useful for experiment setup, including alignment and
focusing, when it is necessary to have the most current image displayed on the screen. It
is also useful when data collection must be coordinated with external devices such as
external shutters and filter wheels. As seen in Figure 15, in Safe Mode operation, the
Mode Shutter
Free Run Normal
External Sync Normal
External Sync PreOpen
Continuous Cleans Normal
Continuous Cleans PreOpen
Table 5. Camera Timing Modes
Chapter 5
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