Princeton Instruments PI-MAX 3 System, Manual, Page: 50 / 150

50 PI-MAX
®
3 System Manual Version 1.A
Note: The intensifier gain also affects the Equivalent Background Illumination (EBI) of
the intensifier. One result of this is that, to properly perform background subtraction, a
new background must be taken whenever the intensifier gain is changed.
Intensifier Mode
The Intensifier Mode selection determines whether the intensifier will be biased on or off
by the defined pulser gate timing (Gate Mode) or it will be continuously biased off until
Gate mode is selected (Safe Mode).
Experiment Setup|Timing
Experiment setup requires the selection of a
variety of experiment timing parameters. The
parameters described in this section are those
that appear on the
Experiment Setup|Timing
tab (Figure 19). With the exception of Fast
Mode/Safe Mode, which is described in full,
the following paragraphs briefly describe these
timing parameters. The settings appropriate to
the intensifier mode and selected pulser are
discussed in Chapter 7 "Gated Operation.
Timing Mode
The timing mode parameter refers to the
PI-MAX3's synchronization of data
acquisition with an external TTL signal applied
to the
TRIGGER IN connector on the back of
the camera or an internal trigger generated by
the internal timing generator. The modes
available depend on the selected intensifier
mode (
Safe or Gate ) and the selected pulser
( SuperSYNCHRO ).
Figure 19. Experiment Setup|Timing
dialog box
Fast Mode or Safe Mode
The Fast Mode or Safe Mode selection determines whether the PI-MAX3 will run the
experiment according to the experiment timing, with no interruptions from the computer,
or the computer will interrupt the acquisition flow to process each frame as it is received.
Figure 20 compares the two modes.
Note:
The Safe Mode on the Timing tab page is not the same as the Intensifier Safe
Mode on the Main tab page.
Fast Mode operation is primarily for collecting “real-time” sequences of experimental
data, where timing is critical and events cannot be missed. Once the PI-MAX3 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