Princeton 4411-0087 Manuale Utente

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 Chapter 
Timing Modes 
Introduction 
Mode 
Shutter 
Free Run 
Normal 
External Sync 
Normal 
External Sync 
PreOpen 
External Sync with 
Continuous Cleans 
Normal 
External Sync with 
Continuous Cleans 
PreOpen 
The Princeton Instruments ST-133 
Controller has been designed to allow the 
greatest possible flexibility when 
synchronizing data collection with an 
experiment.  
The chart to the right lists the timing mode 
combinations. Use this chart in 
combination with the detailed descriptions 
in this chapter to determine the optimal 
timing configuration. 
Table 3.  Camera Timing Modes  
Fast Mode or Safe Mode 
The WinView/32 Experiment Setup 
Timing tab page allows the user to choose Fast 
Mode or Safe Mode. Figure 9 is a flow chart comparing the two modes. In Fast Mode 
operation, the ST-133 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 ST-133 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 ST-133 is sent the 
Start Acquisition command 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 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 , in Safe Mode operation, the computer 
controls when each frame is taken. After each frame is received, the camera sends the 
Stop Acquisition command to the camera, instructing it to stop acquisition. Once that