ADLINK ACL-8216 - Manual (Page 72)

64 • Calibration & Utilities
6.4 D/A Adjustment
There are two steps to calibrate the analog output channels, D/A 1 and D/A 2.
The first step is to adjust the reference voltage, and the second step is to
adjust each channel of D/A.
6.4.1 Reference Voltage Calibration
1. Set reference voltage as -5V ( the D/A reference voltage is selected
by JP1, see section 2.11).
2. Connect VDM (+) to CN3 pin-11 ( V.REF) and VDM(-) to GND.Trim
the variable resister VR6 to obtain -5V reading in the DVM.
Note: If the reference voltage set as -10V, the connection is the same as -
5V, but the reading from DVM should be -10V.
6.4.2 D/A Channel Calibration
D/A CH1 calibration:
1. Connect VDM (+) to CN3 pin-30 ( AO1) and VDM(-) to A.GND.
2. Write the digital value 0x0FFF into registers ( BASE+ 4 and BASE+
5)
3. Trim the variable resister VR3 to obtain +5V reading in the DVM.
D/A CH2 calibration:
1. Connect VDM (+) to CN3 pin-32 ( AO2) and VDM(-) to A.GND.
2. Write the digital value 0x0FFF into registers ( Base + 6 and + 7).
3. Trim the variable resister VR4 to obtain +5V reading in the DVM.
A calibration utility is supported in the software diskette which is included in
the product package. The detailed calibration procedures and description can
be found in the utility. Users only need to run the software calibration utility
and follow the procedures. You will get the accurate measure data.