Specifications

Appendix B PTG Module 67
Operating modes
Continuous: Pulse Width and Pulse Delay remain constant over the course of the
measurement for all triggers.
Sequential: Pulse Width, Pulse Delay, or both change as the measurement progresses.
Fixed: Incremental change in Pulse Width and/or Pulse Delay is constant for each
trigger.
Exponential: Incremental change in Pulse Width and/or Pulse Delay varies with
each trigger; well suited to fluorescence decay experiments.
Anticipated Trigger: Allows bracket pulsing operation with repetitive trigger source
having a fixed period. Hardware determines trigger period and starts bracket pulse at
specified interval prior to trigger.
Trigger
Modes:
Internal: PTG generates triggers at the specified frequency; each trigger initiates a
pulse ensemble that is applied to PI-MAX.
External: Each trigger applied to Ext. Trig. In BNC initiates a pulse ensemble that
is applied to PI-MAX.
Readout Cycle: Readout cycle is triggered through the ST-133A backplane if Int.
Sync. is selected on Experiment Setup Timing tab page.
Enabling: Handshakes that prevent a readout from occurring while the PTG is busy and
that prevent the PTG from pulsing the photocathode ON while a readout cycle is in
progress are performed through the backplane.
External Trigger:
Levels: -6 V to + 6 V DC
External Level Resolution: 48 mV
Slope: selectable.
Coupling: AC and DC selectable.
Input Hysteresis: 100 mV
Repetition Rate: up to 1 MHz
Bandwidth: 700 MHz
Internal Trigger:
Repetition rate:
minimum: 0.1 Hz
maximum: 1 MHz
resolution: 12.5 ns