Princeton Home Security System PI MAX2 User Manual

PI-MAX2 DIF Camera  
(Dual Image Feature)  
Introduction  
This technical note assumes a basic understanding of the operation of the PI-MAX2 and  
PTG in Gate Mode using WinView or WinSpec. Please refer to Chapter 7 of the  
PI-MAX/PI-MAX2 system manual if you do not feel confident with the basic operation  
of the PI-MAX and PTG in Gate mode.  
The purpose of the PI-MAX2 DIF system is to acquire a pair of gated images in rapid  
succession. The time between frames can be as short as 2 µs with exposure times as short  
as 5 ns. The DIF capability is ideally suited to capturing rapidly evolving events. These  
experiments will fall into one of two broadly applicable categories: single trigger and  
dual trigger experiments. Single trigger experiments involve a single impulse event that  
evolves over time such as a laser-induced plasma or luminescence decay. Dual trigger  
experiments involve two impulses separated in time such as double laser pulse  
velocimetry measurements.  
Requirements  
The following requirements must be met for DIF operation:  
the PI-MAX2 must use an interline CCD,  
the controller must have a High Speed PCI Interface (TAXI) board and a PTG  
board installed, and  
the entire system must be set up for DIF operation at the factory.  
In addition to these requirements, it is recommended that the intensifier have a fast decay  
phosphor (P46 or P47). Since DIF operation involves acquiring images in rapid  
succession, phosphor persistence can become the limiting factor in the rate of image  
acquisition.  
WinView or WinSpec software (version 2.5.16 or later) can control the DIF functionality  
of the PI-MAX2 and provides full access to the two DIF timing modes: single trigger and  
dual trigger.  
Interline CCD Operation  
An interline CCD consists of alternating columns of light sensitive pixels and storage pixels.  
The light sensitive columns are referred to as the active area and acquire the image. The  
storage pixels are called the masked area and store the image in the dark while it is read out.  
With this architecture, the CCD can acquire a second image while the first image is being  
read out, unlike a standard CCD, which must read out the first image before the second  
acquisition can begin. The ability of the interline CCD to quickly transfer an image under the  
masked columns and hold it there makes DIF possible. As soon as the first image is acquired,  
Princeton Instruments  
1 of 8  
May 26, 2004  
E:\Manuals\Systems\PI-MAX\PI-MAX2 DIF Camera.doc  
 
PI-MAX2 DIF Camera  
Dual Trigger Mode  
The Dual Trigger Mode requires two triggers to acquire both images of the DIF operation.  
The PTG will control the gating of the intensifier for both images. To make the gate width  
and delay the same for both images, select Repetitive Mode from the Gating tab of the  
Pulser dialog then click the Setup button to set the values. To make the gate width and delay  
different for each pulse, select Sequential Mode from the Gating tab of the Pulse dialog,  
then click the Setup button to set the values. The Number of Images should be set to 2, and  
the first image will use the starting values for gate width and delay while the second image  
will use the ending values.  
Trigger  
Gate  
Gate  
Delay  
Delay  
Gate  
Gate  
Width  
Width  
Intensifier Gate  
SCAN  
2 µs  
400 ns  
400 ns  
Shutter  
Shutter Comp.  
Shift  
first image  
Read out  
both images  
CCD Operation  
Shutter Comp. = Phosphor Decay Time  
Figure 2. DIF Operation: Dual Trigger Timing Diagram  
Princeton Instruments  
3 of 8  
May 26, 2004  
E:\Manuals\Systems\PI-MAX\PI-MAX2 DIF Camera.doc  
 
PI-MAX2 DIF Camera  
Setup  
Hardware  
PTG  
110/220  
EXT. TRIG. IN  
ST-133 Controller  
Trig IN  
PRE. TRIG. IN  
Camera Camera  
Serial Com  
6050-0148-CE  
Pwr  
Signal  
T0  
6050-0499  
TIMING GEN.  
110/220  
GPIB  
6050-0406  
*
Computer  
AUX. TRIG. OUT  
Timing Power Signal  
Gen  
Spectrograph  
Acton 300i**  
PI-MAX2  
110/220  
TRIG.  
*
In current systems, the Timing Gen. cable can remain connected  
during Shutter Mode operation. Older systems may require that it be  
disconnected.  
** Spectrograph connection is optional.  
Figure 3. System Diagram: DIF Operation  
Software  
For the purposes of this setup, it is assumed that you are using either WinView or  
WinSpec to control the system.  
Operation  
The operation of the PI-MAX2 in DIF mode is similar to the standard operation of a  
PI-MAX2 with PTG. There are only a few differences due to the special timing modes of  
DIF, and they will be outlined here. Because there are two timing modes in DIF  
operation, there are two procedures for setting up the experiment.  
Single Trigger Mode  
1. The first requirement is that the PI-MAX2 camera be aligned and focused on the  
area of interest in the experiment. This is best accomplished while the PI-MAX2  
is operating in Interline mode (i.e., before switching to DIF mode). The  
procedure for initial focus is outlined in Chapter 4: First Light of the PI-MAX/PI-  
MAX2 system manual.  
2. After the alignment and focus, the PI-MAX2 system needs to be put into DIF  
mode. Select Hardware from the Setup menu to open the Hardware dialog.  
Under Readout Mode, select DIF and then click OK  
.
May 26, 2004  
4 of 8  
Princeton Instruments  
E:\Manuals\Systems\PI-MAX\PI-MAX2 DIF Camera.doc  
 
PI-MAX2 DIF Camera  
3. The PI-MAX2 must be set to Gate mode for the intensifier to operate properly.  
Either click on the Gate mode button on the Custom Toolbar or select Gate  
mode on the Acquisition|Experiment Setup…|Main tab.  
4. Now the PTG needs to be programmed to match the experiment. On the Setup  
menu, select Pulser and click on Pulser Setup (or click the Pulser Setup  
button in the Custom Toolbar).  
a. In the Pulser dialog, select the Trigger tab. The PTG can be triggered by an  
external trigger signal such as a TTL (typical settings for a TTL trigger might  
be: 1.7 V, positive edge, DC, 50 Ohm) or a photodiode (typical settings for a  
photodiode might be: 8.0 V, positive edge, DC, high Z), or the PTG can use  
its own internal clock to trigger the experiment. Select the appropriate one  
for your experiment. In either case, the trigger frequency should be slow  
enough so that the period between triggers is longer than the entire DIF  
experiment. For example, if the Burst Period is 6 µs, then the trigger  
frequency should be 8333 Hz [1 / (2 * 6 µs)].  
b. Now select the Gating tab. In the Burst Mode section, turn Burst Mode on.  
Set the Number of Pulses to 2. The Burst Period must be set to a value that is  
greater than Gate Width + Gate Delay + Phosphor Decay. Ensure that the  
Gating is set to Repetitive, and then click on the Setup button to set the  
appropriate gate width and delay.  
c. At the bottom of the Pulser Setup dialog, click OK to download the gating  
sequence to the PTG.  
5. The CCD parameters need to be set to the appropriate values for DIF operation.  
Select Experiment Setup from the Acquisition menu.  
a. In the Timing tab, select Single Trig. Mode.  
b. In the Main tab, verify that the Number of Images is 2 and the Intensifier is  
in Gate Mode.  
c. When the experiment is ready, click the Acquire button to start the image  
acquisition.  
Dual Trigger Mode  
1. As with Single Trigger Mode, the PI-MAX2 camera must first be aligned and  
focused on the area of interest in the experiment. This is best accomplished while  
the PI-MAX2 is operating in Interline mode (i.e., before switching to DIF mode).  
The procedure for initial focus is outlined in Chapter 4: First Light of the  
PI-MAX/PI-MAX2 system manual.  
2. The PI-MAX2 system needs to be put into DIF mode. In the Setup menu, open  
the Hardware dialog. Under Readout Mode, select DIF and then click OK  
.
3. The PI-MAX2 must be set to Gate mode for the intensifier to operate properly.  
Either click on the Gate mode button on the Custom Toolbar or select Gate  
mode on the Acquisition|Experiment Setup…|Main tab.  
Princeton Instruments  
5 of 8  
May 26, 2004  
E:\Manuals\Systems\PI-MAX\PI-MAX2 DIF Camera.doc  
 
PI-MAX2 DIF Camera  
4. Now the PTG needs to be programmed to match the experiment. In the Setup  
menu, select Pulser and click on Pulser Setup (or click the Pulser Setup  
button in the Custom Toolbar).  
a. In the Pulser dialog, select the Trigger tab. The PTG can be triggered by an  
external trigger signal such as a TTL (typical settings for a TTL trigger might  
be: 1.7 V, positive edge, DC, 50 Ohm) or a photodiode (typical settings for a  
photodiode might be: 8.0 V, positive edge, DC, high Z), or the PTG can use  
its own internal clock to trigger the experiment. Select the appropriate one  
for your experiment. In either case, the trigger frequency should be slow  
enough so that the period between triggers is longer than the Gate Delay +  
Gate Width + Phosphor Decay time.  
b. Now select the Gating tab. If the experiment can use the same gate width  
and delay for both frames, then select Repetitive, and click on the Setup  
button to set the appropriate gate width and delay. If the experiment requires  
different gate widths or delays for each frame, then select Sequential and  
click on the Setup button to set the appropriate gate widths and delays. The  
number of images should be set to 2, the gate width and delay for the first  
frame should be set as the starting values, and the width and delay for the  
second frame should be set as the ending values.  
c. At the bottom of the Pulser Setup dialog, click OK to download the gating  
sequence to the PTG.  
5. The CCD parameters need to be set to the appropriate values for DIF operation.  
Select Experiment Setup from the Acquisition menu.  
a. On the Timing tab, select Dual Trig. Mode.  
b. On the Main tab, verify that the Number of Images is 2 and the Intensifier is  
in Gate Mode.  
c. When the experiment is ready, click the Acquire button to start the image  
acquisition.  
Tips and Tricks  
Experiments using the DIF feature of the PI-MAX2 can be complex, and timing of the  
events is usually rather exacting. Here are several points to consider that may make the  
experiment setup or troubleshooting much smoother and easier.  
The most important piece of equipment in a DIF experiment is an oscilloscope.  
The PI-MAX2 has a Gate Monitor signal on the back of the camera head which  
is very useful for seeing when the two image exposures occur during the course  
of the experiment. The use of the Gate Monitor and an oscilloscope is discussed  
in more detail in Chapter 11: Tips and Tricks.  
Note: If you have an older version of the PI-MAX/PI-MAX2 system manual,  
refer to Chapter 10.  
The short time between the two images in DIF requires an intensifier with a fast  
phosphor. P46 phosphor as a decay time of ~ 2 µs, that means it takes 2 µs for  
May 26, 2004  
6 of 8  
Princeton Instruments  
E:\Manuals\Systems\PI-MAX\PI-MAX2 DIF Camera.doc  
 
PI-MAX2 DIF Camera  
the phosphor emission to drop to 10% of its peak value. The decay is not a  
simple single exponential; even after 100 µs there may be 1% or more of the first  
image on the phosphor screen. It is usually possible to subtract a percentage of  
the first image from the second image to remove the residual image. If this is not  
possible, there are intensifiers with P47 phosphor, which is an order of magnitude  
faster than P46.  
The software uses the Shutter Compensation Time to determine how long to wait  
after the gate pulse to shift the image. This value can be adjusted in the Hardware  
Setup dialog. If there is some residual image from the first frame in the second  
frame, simply increase the Shutter Compensation Time to allow the phosphor  
more time to decay before shifting the image. If residual image is not an issue,  
then Shutter Compensation Time can be shortened to decrease the time between  
the two DIF images.  
Princeton Instruments  
7 of 8  
May 26, 2004  
E:\Manuals\Systems\PI-MAX\PI-MAX2 DIF Camera.doc  
 
PI-MAX2 DIF Camera  
This page intentionally left blank.  
May 26, 2004  
8 of 8  
Princeton Instruments  
E:\Manuals\Systems\PI-MAX\PI-MAX2 DIF Camera.doc  
 

Pentax Automobile Electronics zoom 70 r User Manual
Pentax Digital Camera Optio MX4 User Manual
Philips Electric Toothbrush B400 User Manual
Philips Portable Speaker SBA220 00 User Manual
Philips Projector Head Hall C13 User Manual
Philips Work Light P 2494 C User Manual
Photogenic Professional Lighting Power Supply PowerLight 1250 User Manual
Pioneer MP3 Docking Station XW NAS3 User Manual
ProForm Treadmill 831296750 User Manual
PYLE Audio Computer Drive PAD10MXU User Manual