National Instruments AT-MIO-16X - Manual (Page 216)

Chapter 6 Calibration Procedures
AT-MIO-16X User Manual 6-4 © National Instruments Corporation
When the AT-MIO-16X board is powered on, or the conditions under
which it is operating change, the calibration DACs should be loaded
with values from the EEPROM, or if desired, the board can be
recalibrated. The AT-MIO-16X calibration process is not difficult or
lengthy, and requires no external equipment (other than wires to
connect the analog output to the analog input). Calibration is performed
by calling the MIO_Calibrate function in NI-DAQ. The function
calibrates the board and performs the necessary EEPROM reads and
writes and calibration DAC writes.
The EEPROM is a 128-bit by 8-bit storage area which contains a
permanent storage area and a modifiable storage area. The permanent
storage area consists of locations 96 through 127. While at the factory,
these locations can be accessed for a read or a write operation, but in the
field, these locations can only be read from. These locations cannot and
should not be written to. This allows for a permanent set of calibration
values that cannot be erased. The modifiable area consists of locations
0 through 95. These locations can always be read from and written to.
Included in this area are the load area, user areas, and user reference
areas. Notice that the load area contains constants that are loaded at
initialization by the software to place the board in a known and
calibrated state.
102 Factory DAC Channel 0 Unipolar Offset
101 Factory DAC Channel 1 Unipolar Gain
100 Factory DAC Channel 0 Unipolar Gain
99 Factory ADC Unipolar Postgain Offset Fine
98 Factory ADC Unipolar Postgain Offset Coarse
97 Factory ADC Unipolar Gain Fine
96 Factory ADC Unipolar Gain Coarse
Table 6-1. EEPROM Factory Area Information (Continued)
Location Location Description