Dg-535 And Gate Mode Overview; Timing Modes; External Sync; Table 7. Timing Mode, Shutter Control, And Ext. Trigger Input When A Dg535 Is The Timing Generator - Princeton Instruments PI-MAX System Manual

Chapter 8

DG-535 and Gate Mode Overview

For gate mode operation with a DG535 Timing Generator, External Sync with PreOpen
timing must be selected ( Acquisition|Experiment Setup...|Timing tab). A "frame
cycle" is initiated by the D output of the DG535 that must be applied to the Ext Sync
input of the ST-133. Without this connection and mode selection, an exposure and
readout cannot occur.
A frame cycle consists of an "exposure" followed by a readout. The "exposure" defines
the time "space" in which the data gets collected. If, as is generally the case, you want the
readout to begin as soon as possible after Ext Sync is applied, set the Exposure Time
to Zero and the Shutter Type (WinView/32 or WinSpec/32 Hardware Setup) to None
(the latter setting removes the shutter compensation time, another source of delay).
The Accumulations and Images parameters ( Acquisition|Experiment
Setup...|Main tab) govern how the data will be processed and whether any given Ext
Sync signal will initiate a controller cycle or be ignored. Integrating multiple events on
the CCD really brings the power of the PI-MAX to bear on low-light gate-mode
experiments. If the experiment allows, many pulses can be summed on the CCD with no
pulse artifacts in the readout. The signal increases nearly linearly with the number of
pulses (within limits imposed by the CCD).
Examples:
1. If you want to acquire 5 separate images, set the ET=0, Number of Images (or
2. If you want to acquire single image that is the sum of integration during 5 gate

Timing Modes

The Timing mode determines when and how the data will be read out. Table 7 shows the
possible Timing Mode and Shutter Control combinations when operating in Gate Mode.
As shown in the table, the following timing modes are available: External Sync and
External Sync with Continuous Cleans.

External Sync

External Sync with Continuous Cleans
External Sync
External synchronization uses the External Sync trigger from the DG535's D output to
determine when the data is readout of the array (Exposure Time = 0 sec.) or when the
exposure time will begin (Exposure Time > 0 sec.). Because of pulser constraints,
External Sync mode must always be used with the PreOpen shutter mode, which ensures
that the DG535 is not "Inhibited" from gating the photocathode while the array is ready
to integrate signal.
Gated Operation with a DG535
Spectra)=5, and Accumulations=1.
pulses, set the ET so that it is long enough to encompass 5 gate pulses, Number
of Images (or Spectra)=1, and Accumulations=1.
Timing Mode
Table 7. Timing Mode, Shutter Control, and Ext. Trigger Input
when a DG535 is the Timing Generator
"Shutter" Control Ext Trigger Input
PreOpen
PreOpen
109
Ext Sync BNC
Ext Sync BNC