Specifications

Guide to Operation - Menus
27
COUNT is A,B FOR T PRESET, then the D/A
output can follow either A or B.
D/A RANGE= LOG
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The D/A output scale can be either logarithmic or
linear. If the output is logarithmic, the scale is 1V
per decade with 1 count being 0V, 0 counts being -
1V, and negative counts being -2V. If the scale is
linear, the output is proportional to 3 digits of the
count. These digits are shown while the ignored
digits are represented by #'s.
The D/A output is updated at the end of each
COUNT PERIOD. If the D/A output is driving a
chart recorder, the end of scan mode should be
STOP or the pen reset will mar the graph. If the
DWELL output is connected to the recorder pen
lift, data will be plotted as unconnected points,
otherwise, the discrete points will be connected.
DISPLAY= CONTINUOUS
HOLD
The count data on the upper line of the LCD can
be updated in two ways. CONTINUOUS mode
updates the display 20 times a second during the
COUNT PERIOD. Data is held during the
DWELL time at the final value reached during the
previous COUNT PERIOD. HOLD updates the
display only at the end of each COUNT PERIOD.
CONTINUOUS is useful when COUNT
PERIODS are long, HOLD is better when
COUNT PERIODS are short.
LEVEL MENU
TRIG SLOPE= RISE
FALL
The gate generator may be triggered on either the
rising or falling edge of the TRIGGER input.
TRIG LVL=+2.000 V
The gate TRIGGER threshold level may be
adjusted from -2.000 V to +2.000V. The
discriminated trigger pulses may be viewed
through the T DISC output when counter T is
preset and its input is TRIG. This can be helpful in
selecting a trigger level. The minimum pulse
amplitude required to trigger is 100 mV.
A DISC SLOPE= RISE
FALL
When A counter's input is INPUT 1, A
discriminator may be triggered by rising or falling
edges of the INPUT 1 signal. If the signal pulses
are negative going, then the slope should be
FALL. If the signal pulses are positive, then the
slope should be RISE. In either case, the A DISC
output is always active low; i.e., a discriminated
rising edge of the signal will be output as a
negative going NIM pulse at the A DISC output.
The falling edges of the A DISC output are
counted by counter A.
A DISC= FIXED
SCAN ∆= -1.0 mV
The threshold level of A discriminator may be
FIXED or SCANned. If the level is fixed, the right
hand parameter is not displayed. If the level is
scanned, then the right hand parameter is the step
size. At the end of each count period in a scan, the
level is incremented by one step size. The step size
can be varied from -20.0 mV to + 20.0 mV. The
range of a scan is N PERIODS times the step size.
The starting level is set in the next menu line.
The scan mode may be changed during a scan. If it
is changed to SCAN, the level begins scanning
from the start value on the next count period. If it
is changed to FIXED, the level returns to the start
level immediately.
The step size may also be changed during a scan.
The new step size will be in effect at the end of the
next count period. The scan is not reset or paused.
A DISC LVL = -10.0 mV
: -11.0 mV
The threshold level of A discriminator may be
adjusted from -300 mV to + 300 mV. This level is