DSA Support

Testing Your NI 455X Instrument

You may test your NI 455X instrument by using the NI-DAQ driver software through the Measurements & Automation Explorer (MAX). In this mode, the NI 455X board will behave as if it were a PCI-445X board, so it will not use the onboard processor.

You may also test your NI 455X instrument by using the NI-DSA driver software through VirtualBench-DSA. In this mode, the NI 455X board will behave as a real-time instrument and it will use the onboard processor.

(Note: You will need a 50 Ohm or 75 Ohm BNC cable if you wish to perform an acquisition test through the BNC-214X signal accessory.)

Launch the Measurement & Automation Explorer (this ships with NI-DAQ 6.5 or higher). Look for the blue and yellow icon on your Windows Desktop (as shown below) and double-click it.
Once in the top level window of the Measurement & Automation Explorer, double-click on "Devices and Interfaces", then double-click on your NI 455X device.
Double-click on the label "Device Number" and the Configuration window will open.
Note: The resources shown in this window may differ from the ones that you will see.
Launch the NI-DAQ Test Panels by pressing the Run Test Panels button.
Click on the Analog Input tab, and select the channel number you wish to test. Enter an appropriate sampling rate, then click on the Continuous button to start a continuous acquisition of the time domain signal. Changing the Input Limits will alter the gain the board uses to read the channel data.

It is important to select the Input Limits according to the maximum and minimum voltage values of your signal, in order for the board to use the correct amplification or attenuation factors and to acquire the signal across the entire 16 bits of ADC (analog to digital converter) resolution of the delta-sigma converters.
Your choice of Input Limits will depend on the input range and gain specifications of your DSA hardware. The NI 4551 and the NI 4552 have gains from -20 dB to 60 dB in 10 dB increments; that is:
Connect a known signal to the input either directly or through a transducer, by using the BNC-214X channel connectors.
Alternatively, if you have an NI 4551 board with two inputs and two outputs, then you can perform a simple feedback test. Use a feedback BNC cable to connect Output Channel 0 to Input Channel 0, and then click on the Analog Output tab to start a sine wave generation. Make sure that your parameters look the same as the ones shown in the window (below) and click on the Start Sine Generator button. After starting the sine wave output, go to the Analog Input tab and start a continuous acquisition. You should see the output waveform on the Analog Input waveform graph.

This quick test confirms that the board is working properly in DAQ mode, that the resources were allocated correctly, and that the communication between the NI-DAQ driver and the hardware is working properly.

Before going any further, close (exit) the Measurments & Automation Explorer.

Now perform the functionality test using NI-DSA through VirtualBench-DSA for the NI 455X instruments.

Launch VirtualBench-DSA (version 2.5 or higher). Make sure that the Measurement & Automation Explorer is closed and that you are not performing any type of acquisition with the board.
Note: If VirtualBench-DSA hangs during launch or in any of the steps described below, make sure that you have the latest version of NI-DSA and the latest version of VirtualBench-DSA.
Select Edit » Reset Settings. This step is important, because it ensures that you use the default settings for the test described below.
Select Edit » Input Settings.
Click on the Input tab and make sure that the Device is an NI 455X board. Check that the settings are similar to those shown below.
Click on OK to return to the main VirtualBench-DSA window. Make sure that the Run button is selected. You should see a Time Domain Record on the upper display and an Amplitude Spectrum on the lower display. The Amplitude Spectrum will be from a 400 FFT line measurement performed on your 0 to 20 KHz input signal on Channel 0. Input a known sine wave with an amplitude within the +-10 V range selected with the Range control on the Input tab. A peak at the fundamental frequency of your input sine wave should be evident in your frequency spectrum.
If you have an NI 4551 board with two inputs and two outputs you can use a BNC cable to feedback Output Channel 0 to Input Channel 0 on the BNC-214X terminal block. You can generate a sine wave with the board, read it back, and then analyze its frequency component.
To do this, select Edit » Source Settings, then choose the desired frequency and amplitude for Tone 1 (sine wave).
Make sure that the amplitude is not zero for Tone 1 (e.g., use 1 V). Then click on On button and you should see the sine wave on the main screen along with its Amplitude Spectrum. If you are using the BNC-2140 accessory, make sure that the integrated circuit piezolelectric Power is OFF.
This test confirms that the NI-DSA driver is working correctly with the hardware and that the onboard instrument engine is running and communicating with the host.