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National Instruments Corporation
7
6703/6704 Calibration Procedure
Verifying Your Board’s Operation
Verification determines how well the board is meeting its specifications.
By performing this procedure, you can see how your board has operated
over time. This information can help determine the appropriate calibration
interval for your application.
The verification procedure is divided into the major functions of the device.
Throughout the verification process, use the tables in the
Accuracy
Specification
section later in this document to see if your device needs to
be calibrated.
Verifying Voltage Output
This procedure checks the operation of the board by verifying that the
output of voltage channel zero is within specifications. Because of the
channel-to-channel matching of the 6703/6704 voltage channels, if voltage
channel zero is operating within specifications, all the voltage channels
should be operating within specifications. However, if you want to verify
the channels individually, this procedure can be easily expanded to verify
all the voltage channels by performing the procedure once for each voltage
channel. To do this, perform the procedure once for each value of the
channel parameter from 0 to 15. Each time you repeat the procedure, you
will also need to connect the appropriate channel to your DMM. See the
PCI/PXI-6703/6704 User Manual
for the pin numbers corresponding to
each channel. To verify the voltage output, make sure that you have read
the
Equipment and Other Test Requirements
sections covered previously,
and follow these steps:
1.
Run the
Get_Cal_Date
function contained in
ni6704Cal.dll
to
check the board’s previous calibration date.
2.
Connect the DMM to the board as shown in the following table:
3.
Place the DMM in voltage mode.
4.
Run
AO_VWrite
with
chan
set to 0 and
voltage
set to 0.0. This will
output 0.0 V on voltage channel 0.
5.
Compare the resulting value shown by the DMM to the upper and
lower limits listed in
section later in this document.
If the value falls between these limits, the test is considered to have
passed.
Signal Name
Description
6703/6704 Output
DMM Input
VCH0
Voltage Channel 0
Pin 34
High
AGND0
Analog Ground 0
Pin 68
Low