Instructions
8845A/8846A 
Users Manual 
3-16 
F1 F2 F3 F4 F5
caw056.eps 
Figure 3-2. Histogram Display 
In addition to the bar graph, the left third of the display also displays the number of 
samples, the average, and standard deviation values. 
To start a histogram session: 
1.  Set up the Meter for the desired measurement by selecting the function, and 
connecting the signal to the Meter’s input. 
2.  With the Meter taking measurements, press J. 
3.  Press HISTOGRAM to start the session. 
The display will start adjusting the bar graph as the number of readings accumulates. The 
mean and standard deviation values also change in accordance with the collected 
readings. 
To start the histogram session over, press the STOP soft key followed by the 
RESTART soft key. 
To stop the histogram session, press B or the STOP soft key. 
Controlling Trigger Functions 
The Meter’s trigger functions allows you to select a measurement trigger source, set the 
number of measurements (samples) per trigger, and set the delay time between receiving 
the trigger and the start of a measurement. In addition, the trigger function provides a 
“measurement complete” signal on the trigger port on the rear panel. See item 5 in 
Table 3-3. Triggering the Meter remotely through one of its communication interfaces is 
covered in the Programmers Manual. The following sections discuss triggering the Meter 
automatically (internal trigger), or externally using the trigger key on the front panel and 
the trigger connector on the rear-panel. 
Setup and control of the trigger function is accessible through the Meter’s Measurement 
Setup key L. 
Choosing a Trigger Source 
There are four possible sources for triggering a Meter measurement: automatic, front 
panel trigger key W, external, and remote. With the exception of remote triggering, 
trigger source selection is through the trigger menu, found under the measurement setup 
menu. 
To select a trigger source: 
1.  Press L to see the measurement setup menu. 
2.  Press the TRIGGER soft key to reveal the trigger control selections. 










