Princeton Instruments PI-MAX 3 System, Manual, Page: 51 / 150

Chapter 5 General Operation Factors 51
priority, so the image on the screen may lag several images behind. 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 20, in Safe Mode operation, the
computer controls when each frame is taken. After each frame is received, the detector
sends the Stop Acquisition command to the detector, instructing it to stop acquisition.
Once that frame is completely processed and displayed, another Start Acquisition
command is sent from the computer to the detector, allowing it to take the next frame.
Display is therefore, at most, only one frame behind the actual data collection.
One disadvantage of the Safe mode is that events may be missed during the experiment,
since the PI-MAX3 is disabled for a short time after each frame.
Delay Time
Allows a delay to be inserted between successive frame acquisitions. This parameter is only
active in Safe Mode operation, in which each frame must be completely processed before the
next one can be taken. The Delay Time inserts an additional delay after the computer has
finished processing the previous frame before the next one can be acquired.