ADLINK PCM-9112+ - Manual (Page 86)

78 • Calibration
6.4 D/A Adjustment
There are two steps in calibrating the analog output channels, D/A 1 and D/A
2. The first step is to adjust the reference voltage for the D/A channel, and
then adjust the full range of each D/A channel.
6.4.1 Reference Voltage Calibration
1. Set the reference voltage as -5V (Refer to section 2.8 to see the
internal reference setting).
2. Connect the DVM (+) to CN3 pin-11 (V.REF) and DVM (-) to GND.
Trim the variable resister VR6 to obtain a -5V reading on the DVM.
Note: If the reference voltage is set as -10V, the connection is the same as
the -5V, but the reading on the DVM should be -10V.
6.4.2 D/A Channel Calibration
D/A CH1 calibration
1. Connect the DVM (+) to CN3 pin-30 (AO1) and the DVM (-) to
A.GND.
2. Write the Digital value 0x0FFF into the register at BASE+10 address
3. Trim the variable resister VR3 to obtain a +5V reading on the DVM.