BNC-2121 Connector Accessory for 660X Devices
6
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To make the connection, complete the following steps.
1.
Insert one end of the BNC cable in one of the PFI <32..39>
BNC connectors.
2.
Connect the other end of the BNC cable to the output device.
In addition to the BNC connectors associated with the PFI lines of the
660
X
device, the BNC-2121 has six user-defined BNC connectors,
USER <1..6>, that are associated with six corresponding user-defined
spring terminals USER <1..6>. You can use these BNC connectors for
either input or output.
Testing User-Defined Functions
You can use the BNC-2121 to test the following features on the
660
X
device.
Producing a +5 V Pulse
Use the digital trigger to test an application that counts or measures pulses.
Press the
Digital Trigger
button to produce a +5 V pulse for as long as the
button is pressed, causing the LED to light up. When you release the button,
the trigger line goes low. You can access the digital trigger by connecting
a wire to the
Trigger
spring terminal. The digital trigger also can simulate
a channel Z pulse for quadrature encoder functions.
The lowpass filter on the BNC-2121 is designed to remove glitches on the
trigger output. If you want to use unconditional trigger output to test the
debouncing filter on a 660
X
device, flip the
Filtering
switch to the OFF
position, connect the trigger output to a PFI line, and programmatically
enable the debouncing filter on the 660
X
device. For all other applications,
flip the
Filtering
switch to the ON position.
Measuring Position
The BNC-2121 can produce 24 pulses per encoder revolution. You can test
this feature using the following programs.
•
C interface—
TIOquadEncoderPosMeasure.c
located in
Program Files/National Instruments/Measurement
Studio/CVI/Samples/DAQ/Ctr
•
LabVIEW—Measure Position VI located in
Program Files/
National Instruments/LabVIEW/Examples/DAQ/Counter/
NI-TIO.llb
