D/A Converter Calibration - Z-World Wolf BL2600 User Manual

also affects the resolution of the 4–20 mA current outputs—you need to configure a volt-
age output for unipolar operation if you want 12-bit resolution on the associated current
output.
There are other effects on a current output when the associated voltage output is operating
in the bipolar mode. While voltages of 0 to +10 V still correspond to currents of 4 to 20 mA,
the current cannot be determined reliably for voltages below 0 V, and will be "negative" at
voltages below -2.5 V. Thus the current output effectively becomes a "current sink"
instead of a "current source."
The D/A converter outputs are factory-calibrated and the calibration constants are stored in a
separate EEPROM.

3.5.1 D/A Converter Calibration

To get the best results form the D/A converter, it is necessary to calibrate each mode (uni-
polar, bipolar, and current) for each of its gains. It is imperative that you calibrate each of
the D/A converter outputs in the same manner as they are to be used in the application.
The calibration table in software only holds calibration constants based on unipolar, bipo-
lar, and voltage or current operation.
account by calibrating using the same mode and voltage/current setup as in the intended use.
Sample programs are provided to illustrate how to calibrate the various D/A outputs for
the three operating modes.
Voltage
Current
These sample programs are found in the
Section 4.2.5 for more information on these sample programs and how to use them.
User's Manual
Other factors affecting the calibration must be taken into
Mode
DAC_CAL_VOLTS.C
DAC_CAL_MA.C
subdirectory in
DAC
Calibrate
SAMPLES\BL2600
. See
27