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Synchronizing Mulitple NI WLS/ENET-9215 Devices

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Overview

This example demonstrates how to synchronize two NI WLS-9215 wireless DAQ analog input devices or two NI ENET-9215 Ethernet DAQ analog input devices using the PFI0 and PFI1 trigger pins of the NI WLS-9163 and NI ENET-9163 carriers.

Downloads

Filename: wls-9215_multi-device_synch.vi
Requirements: View

Background

The NI WLS-9163 wireless and NI ENET-9163 C Series carriers each feature a four position trigger connector, providing two digital lines (PFI0 and PFI1) and two ground pins. PFI 0 may be used to import or export a digital trigger to control acquisition based on an external stimulus. In the case of the 9215 AI module, you can use PFI 1 to import or export the aiSampleClock signal to synchronize two or more WLS/ENET-9215 devices.

Instructions for Running

Physical Connections

Make sure your signal input terminal matches the Physical Channel I/O control.

Using the included 4-pin connector, connect PFI 0, PFI 1, GND 0, and GND 1 of the master WLS-9215 to the PFI 0, PFI 1, GND 0, and GND 1 of the slave WLS-9215, respectively (straight-through connection).

Block Diagram Steps

  1. Create an analog input voltage channel for both the Master and Slave devices.
  2. Set timing parameters. Note that sample mode set to Continuous Samples. In this example, the Rate is set the same for both devices, you can however wire in separate controls and run the devices at different samples rates.
  3. Export the aiSampleClock signal to PFI 1 of the master WLS-9215 device. aiSampleClock can only be exported to PFI 1
  4. Set the timing parameters for the slave WLS-9215, specifying PFI 1 as the clock source.
  5. On the master WLS-9215, export the aiStartTrigger to PFI 0
  6. On the slave WLS-9215, Import the start trigger on PFI 0
  7. Call the Start VI to start the acquisition. (Note: The flattened sequence structure is used to ensure the slave device is armed before the Master so that the slave device does not miss the trigger.)
  8. Read all of the waveform data in a While loop. The 'Samples to Read' control will specify how many samples per while loop iteration to read. If either devices report an error or the user presses the 'Stop' button on the front panel, the while loop will exit.
  9. Call the Clear Task VI to stop the acquisition and clear the tasks.
  10. Use the popup dialog box to display an error if any.

Running the Front Panel


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  1. Select the physical channel to correspond to where your signal is input on each DAQ device.
  2. Enter the minimum and maximum voltage range.
  3. Set the rate of the acquisition
    Note: The rate should be at least twice as fast as the maximum frequency component of the signal being acquired.
  4. Set the number of Samples to Read per iteration of the while loop.

Additional Wireless DAQ Resources

Requirements


Filename: wls-9215_multi-device_synch.vi

Software Requirements


Application Software: LabVIEW Base Development System 8.6
Language(s): LabVIEW

Hardware Requirements


Hardware Group: Multifunction DAQ (MIO), Portable DAQ
Hardware Model: ENET-9215, WLS-9215 BNC, WLS-9215, ENET-9215 BNC
Driver: NI-DAQmx 8.8

 
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This example program (this "program") was developed by a National Instruments ("NI") Applications Engineer. Although technical support of this program may be made available by National Instruments, this program may not be completely tested and verified, and NI does not guarantee its quality in any way or that NI will continue to support this program with each new revision of related products and drivers. THIS EXAMPLE PROGRAM IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND AND SUBJECT TO CERTAIN RESTRICTIONS AS MORE SPECIFICALLY SET FORTH IN NI.COM'S TERMS OF USE (http://ni.com/legal/termsofuse/unitedstates/us/).