Pulse Train Output at ±6V with NI C Series Digital Module NI 9477

Updated Jul 25, 2024

Environment

Hardware

  • NI-9477
  • PXI-4130

Software

  • LabVIEW

Driver

  • NI-DAQmx
  • NI-DCPower

I want to output pulse train/square wave signal with digital module, and the difference is the voltage level should be ±6V, which is not match with the spec of NI 9477. Is there any way to achieve it?

You can achieve this function if you connect two external power supplies, one is +6V, one is -6V. The circuit diagram is shown in Figure 1.

Figure 1. Circuit Diagram

Instructions:
  1. Use a SMU PXI-4130 (or equivalent) to generate +6V and -6V power supplies.
  2. Set up the NI 9477 in a compact DAQ chassis.
  3. Use the LabVIEW example of Digital- Continuous Output.vi to generate a pulse train/square wave signal in the DO terminal, see Figure 2.

Figure 2. LabVIEW Example
  1. Use an oscilloscope to view the PWM signal generated at DO. An example can be seen in Figure 3.

Figure 3. Output Waveform
 

Additional Information

The power supply doesn't have to be a NI SMU, any other power supply vendor may be used.  This method can be applied to any voltage generated by a power supply within the hardware spec.