National Instruments SCXI -1125 用户手册

If you are using a C-based ADE, use the following procedure to do an offset 
calibration on the SCXI-1125:

1.

Make sure the DAQ device or DMM you are using has a valid 
calibration and meets the accuracy specifications for your application.

2.

Use the NI-DAQ function 

SCXI_Calibrate

 to calibrate one channel 

of the SCXI-1125.

a.

Enter the DAQ device, DAQ channel, module slot, and module 
channel for the channel you want to calibrate.

b.

Select internal calibration (0) as the operation you are going to 
perform.

c.

Select the load area (1) as the EEPROM area you want to update.

d.

Since offset varies with gain, enter the gain setting for which you 
are calibrating offset.

e.

Enter 

1

 for the terminal block gain since it is not used.

f.

Enter 

0.0

 as the input reference voltage.

3.

Repeat step 2 for calibrating additional channels.

The SCXI-1125 may take a few seconds to perform the calibration. After 
completion, your module will have new calibration constants stored for the 
channels and gains you calibrated.

If you also need to calibrate the gain constants on the SCXI-1125, you must 
use an external reference to perform a two-point calibration. Please refer to 
the SCXI-1125 Calibration Procedures document for more information on 
doing an external two-point gain and offset calibration.

1000

0.005 V

2000

0.0025 V

Table 5-9.  Gain Values and Input Limits (Continued)