Analysis Mode
3.4
Configuration
To enter Configuration mode, press the PARM buttons simultaneously. The four buttons then assume the
functions shown in the CONFIG box. To exit Configuration mode, press the PARM buttons simultaneously
again. This operation does not cause parameters to be adjusted; only button releases are detected in
Configuration mode.
Configuration mode contains a number of adjustable parameters. To scroll through the available
parameters, use the VALUE buttons. To change the parameter values, use the PARM buttons.
Some items in Configuration mode are not parameters, but commands or gateways to a submenu. These
items are labelled as words with a question mark. To enter these items or to execute the command, press
either PARM button.
Although a few of the parameters in the Analysis and Scale configuration menus are the same, the
settings are kept separate between the modes. For example, input channel 1 can be selected in Scale
mode while input channel 2 is selected in Analysis mode. In this setup, when the ADS1232REF switches
from Scale to Analysis mode, the input channel becomes 2.
summarizes the available parameters.
Table 5. Parameters in Analysis Mode
PARAMETER
DISPLAY
VALUE RANGE
DESCRIPTION
Averages
AVG=
2
–
128
Number of points for average,
peak-to-peak, and RMS modes
Voltage Reference
VREF=
0.5
–
5.0
Voltage used in various
calculations
Power-down mode
PDWN?
—
Power-down mode; see
Offset calibration
OCAL?
—
Offset calibration; see
Save parameters
SAVE?
—
Save parameters; see
Version number
V1.1.0
—
Firmware version number display
3.4.1
Parameters
Averages: Number of points to use in Averaged, RMS noise, and Peak-Peak calculations. The choices
available are 2, 4, 8, 10, 16, 32, 50, 64, 100, and 128. The default setting is 50.
Voltage reference: To convert voltages to codes, the ADS1232REF requires the voltage reference level.
Since this level cannot be measured, it must be selected manually. This parameter allows the reference
level to be set.
Each digit of the voltage reference is selected and adjusted separately. Use the VALUE buttons to select
a digit, and the PARM buttons to adjust it. The selected digit flashes.
This parameter does not affect the actual voltage reference used. If it is incorrect, voltage calculations will
be wrong. The voltage reference is typically the +5V rail; the default value for this parameter is 5.0V.
Power-down mode: When either PARM button is pressed on this screen, the ADS1232REF causes the
ADS1232 to enter power-down mode. This action occurs by pulling the PDWN line low. While the PDWN
line is low, the display reads POWER DN. When a button is pressed from this display, the ADS1232REF
powers the converter on and returns to the analysis display, exiting configuration mode.
This mode can be used to test the current consumption of the board when the ADS1232 is powered down.
Offset calibration: When either PARM button is pressed on this screen, the ADS1232REF initiates a
hardware offset calibration on the ADS1232 by providing two extra shift clock cycles on the next data read
cycle, as described in the
.
When either PARM button is pressed, the display briefly shows OK, indicating that calibration was
performed.
Offset calibration is performed when the ADS1232REF is powered on, but is not automatically performed
at any other time.
Version number: This screen displays the version number of the ADS1232REF firmware.
13
SBAU120B
–
November 2005
–
Revised July 2011
ADS1232REF User
'
s Guide
Copyright
©
2005
–
2011, Texas Instruments Incorporated