National Instruments PXI-4130, Calibration Procedure, Page: 33 / 44

NI PXI-4130 Calibration Procedure | © National Instruments | 33
4.
Close session and commit new calibration coefficients
: To complete adjustment of the
range, call the niDCPower Close External Calibration VI (
niDCPower_CloseExtCal
function) to close the session. To write new calibration coefficients to the hardware, specify
an action of
Commit
. At this time, the calibration date and temperature stored onboard are
also updated.
Note
You can adjust any voltage or current range individually by opening a
calibration session, adjusting, and then closing the session with an action of
Commit
.
To adjust all voltage and current ranges simultaneously, open a single calibration
session, execute multiple adjustment steps, and then close the session with an action
of
Commit
to write coefficients for multiple ranges simultaneously.
Note
If the NI 4130 passes initial verification and is within all test limits,
NI recommends, but does not require, an adjustment to guarantee the published
specifications for the next year. If you choose to skip adjustment, run the niDCPower
Initialize External Calibration VI and end with the niDCPower Close External
Calibration VI with
action
set to
Commit
to update the calibration date and onboard
calibration temperature without making any adjustments to the device.
After adjustment, repeat the
Verification
section to verify that the adjustment was successful.
Adjusting Voltage Programming Accuracy
To adjust voltage programming, compare a set of requested voltage output points to the actual
voltage as measured by an external DMM. Configure the voltage level using the
Output
value
for the iteration of channel
x
in Table 18.
To ensure the system has had adequate time to settle, wait one second after requesting a new
voltage before taking a measurement with the DMM.
Use the niDCPower Cal Adjust Voltage Level VI (
niDCPower_CalAdjustVoltageLevel
function) to calculate the new calibration coefficients. Pass the voltage setpoints requested by
the NI 4130 to the Requested Outputs input of the VI and the voltage values measured by the
DMM to the Measured Outputs input of the VI. Call this VI or function once for the positive
setpoints and once for the negative setpoints specified for each range in Table 18.