UG-855 datasheet(16/29 Pages) AD

16 / 29 page

UG-855

EVAL-AD7124-4SDZ User Guide

Rev. 0 | Page 16 of 29

HISTOGRAM TAB

The Histogram tab generates a histogram using the gathered

samples and processes the data, calculating the peak-to-peak

noise, rms noise, and resolution (see Figure 22).

Histogram Graph and Controls

The data histogram graph (Label 1) shows the number of times

each sample of the ADC output occurs. Zoom in on the data

using the control toolbar (Label 6) in the graph. Change the

scales on the graph by typing values into the x-axis and y-axis.

Analysis Channel

The Noise Analysis section and histogram graph show the

analysis of the channel selected via the Analysis Channel

control (Label 2).

Noise Analysis

The Noise Analysis section (Label 3) displays the results of the

noise analysis for the selected analysis channel, which includes

both noise and resolution measurements.

Display Units and Axis Controls

Click the Display Units drop-down list (Label 4) to select

whether the data graph displays in units of voltages or codes.

This control affects both the waveform graph and the histogram

graph. The axis controls can be switched between dynamic and

fixed. When dynamic is selected, the axis automatically adjusts

to show the entire range of the ADC results after each batch of

sample. When fixed is selected, the user can program the axis

ranges; the axis ranges do not automatically adjust after each

batch of sample.

CRC Error and Overall Error

The CRC Error LED indicator (Label 5) illuminates when a cyclic

redundancy check (CRC) error is detected, in the communications

between the software and the AD7124-4. The CRC functionality

on the AD7124-4 is disabled by default and must be enabled for

this indicator to work. The Error Present LED (Label 5) indicates

if an overall error is present in the diagnostics register. For this

indicator to work, the check for the different diagnostic errors

must be enabled in the Error_EN register.

Figure 22. Histogram Tab of the AD7124-4 EVAL+ Software

UG-855 Datasheet(PDF) 16 Page - Analog Devices