NI 9219 Calibration Procedure
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© National Instruments Corporation
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23
b.
Configure the AI bridge (V/V) task timing according to Table 27.
c.
Start the task.
d.
Use DMM1 to measure the excitation voltage from the NI 9219.
e.
Record this measurement as V
ExcitationModule
.
Note
The excitation voltage on the NI 9219 may be off if the module is not
configured correctly. The excitation value on the NI 9219 should be at least 2.5 V.
f.
Clear the task.
5.
Set the voltage source to V
ExcitationModule
. Use the smallest available range needed to source
V
ExcitationModule
. Using a range larger than necessary creates unwanted additional noise.
6.
Connect the NI 9219 to DMM1, DMM2, and the voltage source as shown in Figures 11, 12,
or 13 for the appropriate test point value indicated in Table 30. Observe the following
conditions when connecting the equipment to the NI 9219.
•
Connect the leads of DMM1 as close as possible to the terminals on the NI 9219.
•
Connect the HI lead of DMM2 as close as possible to the same point that the HI lead
of the NI 9219 connects to the resistor network.
•
Connect the LO lead of DMM2 as close as possible to the EX– terminal of the NI
9219.
Table 26.
NI 9219 Configuration for Half-Bridge Accuracy Verification
Measurement
Type
Min (V)
Max (V)
Excitation
Source
Excitation
Value
Bridge
Config
Half-Bridge
500 mV/V
–0.5
0.5
Internal
2.5
Half-Bridge
Table 27.
NI 9219 Timing Configuration
ADC Timing Mode
Sample Timing Type
High Resolution
On Demand