SRS Labs SR430, Manual

Page: 29 / 146

LEVELS MENU
27
-10.0 mV
0.0 V
0.0 V
500 mV
Trigger Level
Trigger Slope
Disc. Level
Disc. Slope
Aux. 1 Level
Aux. 2 Level
LEVELS
Trigger Level
Trigger Slope
Discriminator Level
Discriminator Slope
Aux 1 Level
Aux 2 Level
Introduction
The Levels menu is used to set the trigger and discriminator settings as
well as the Aux output levels.
Trigger Level
Pressing the Trigger Level key selects the trigger threshold level as the
active entry field. A new trigger level may be entered from the numeric
keypad (in units of Volts) or the knob may be used to adjust the present
level. The trigger threshold is adjustable from -2.000V to +2.000V with
1mV resolution. The minimum pulse amplitude required to trigger is 0.1V.
Trigger Slope
The Trigger Slope key changes the trigger slope to either rising or falling
edge.
Discriminator Level
The Discriminator Level key selects the discriminator threshold as the ac-
tive entry field. A new threshold level may be entered from the numeric
keypad (in units of Volts) or the knob may be used to adjust the level.
The discriminator threshold is adjustable from -300mV to +300mV with
0.2mV resolution. The minimum signal pulse amplitude required is 10
mV. The Disc. Out signal is the output of the discriminator. Viewing this
signal on an oscilloscope while adjusting the threshold can be helpful in
determining the appropriate level. See the "Using Photomultipler Tubes"
section later in this manual.
Discriminator Slope
The Discriminator Slope key changes the discriminator slope to either ris-
ing or falling edge. If the input signal pulses are negative going, then the