6.4D/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.

6.4.1Reference Voltage Calibration

1.Set reference voltage as -5V (the D/A reference voltage is selected by JP3, see section 2.8).

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.

6.4.2D/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+ 10)

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 + 14)

3.Trim the variable resister VR4 to obtain +5V reading in the DVM.

A calibration utility is supported in the software CD 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.

In normal condition, the PCI-9112 already calibrated by factor before it is shipped out. So, users do not need to calibrate your PCI-9112 when you get it.

Calibration ∙ 69