Xantrex XTR 850 Watt, Operating Manual

Page: 256 / 286

Calibration and Troubleshooting
B-22 M370046-01
Calibrating the Input Voltage APG Signal
The input voltage APG calibration is necessary to ensure accurate measurements
when using the
:MEAS:APR?
and
:MEAS:APR:ISOL?
SCPI command
queries to monitor the APG input signal.
Gain Calibration
To calibrate the VAP APG input gain:
1. Connect a voltmeter and a DC voltage source to the non-isolated
voltage APG input lines (J1.9 and J1.7).
2. Turn the power supply On.
3. Set the Voltage APG level to 4 V.
Send the SCPI command:
SYST:COMM:APR:LEV 4
4. Set the input source as Voltage analog APG. Send the SCPI
command:
SYST:REM:SOUR:VOLT AVOL
5. Set the voltage source attached to the non-isolated voltage APG input
to 90% of the nominal voltage level, in this case 3.6 V.
6. Turn the output power on.
7. The power supply starts up in Constant Voltage mode.
8. Read the input voltage value from the voltmeter connected in step 1.
9. Type the SCPI input Voltage calibration command with voltage noted
in step 8 as the parameter “data”.
For example, you would type
:CAL:INP:ANAL 3.53
if you were
reading 3.53 volts from the voltmeter.
Offset Calibration
Offset calibration of the power supply provides the best accuracy in low-
range input voltage.
To perform offset calibration:
1. Set the voltage source attached to the non-isolated Voltage APG input
to 10% of the nominal voltage level, in this case 0.400 V.
2. Turn on the output power.
3. Read the input voltage value from the voltmeter connected in step 1
of the gain calibration.