Not Seeing NI Controllers Pop Up under the DAQmx Physical Channels in LABVIEW

[bigbird49]

I'm using LabVIEW 2020 with DAQmx 20.0. I have a PXIe-1084 chassis which is plugged into my computer with a ethernet cable. In NI-MAX I'm able to see all the controllers connected to the chassis but LabVIEW I'm unable to see the controllers when looking under DAQmx Physical Channels. My LabVIEW vi is under the NI Example Finder Hardware Input and Output/DAQmx/Analog Output/Voltage - Continuous Output.vi

NI-MAX:

LABVIEW:

I'm trying to get the physical channel in LabVIEW to be able to connect with NI PXIe-6739 under Remote Systems in NI-MAX but LabVIEW only sees SimDev1 under My System in NI-MAX. Not able to figure out why NI PXIe-6739 under Remote Systems isn't being detected.

[Bob_Schor]

MAX clearly shows you have two "Hardware-capable" Devices:  "My System" (which is your Windows PC running LabVIEW), with not much in the way of hardware other than a Simulated DAQ Device, and a "Remote System", the NI-PXIe8821, which has a lot of plugged in hardware (7 slots worth).  Have you tried clicking on one of these "Remote Devices" (with your PXI turned on and connected via Ethernet to your LabVIEW PC, of course) and seeing if you can open a Test Panel?  [I've got a PXI system sitting in my Office-that-I-haven't-been-into-in-about-two-years, so I can't easily test code for you, and the myRIO on my workbench doesn't have the right "personality" installed to use as a test subject ...].

Bob Schor

[JÞB]

Which module is the Analog Output available on?  I don't have time to see the device spec but,  nothing I see triggers an AO FEELING.

[santo_13]

No, a regular DAQmx driver cannot work with a remote system, the DAQmx device has to be directly connected to the PC running the DAQmx driver.

[bigbird49]

Yes, So I'm able to open the test panel and when I update pins through NI-MAX there voltage and current changes.

[bigbird49]

PXIe-1084 chassis hosting the PXIe-8821 and PXIe-6739 under RT OS. PXIe-8821 allows communication via ethernet between remote system and the computer running LabVIEW.

[rolfk]

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@bigbird49 wrote:

PXIe-1084 chassis hosting the PXIe-8821 and PXIe-6739 under RT OS. PXIe-8821 allows communication via ethernet between remote system and the computer running LabVIEW.

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Of course! But that doesn’t mean that you can access a DAQ hardware through the DAQmx API from your Windows computer. That was possible with some hardware with the old NI-DAQ driver but a known and officially documented limitation with DAQmx.

PXI hardware is only possible to be accessed if the PXI chassis is directly connected to the Windows computer through a MXI or similar PCI bus extension or for some measurement hardware through remote VISA access.

[bigbird49]

Thanks for the information. It helps greatly. Is there any recommend card that we can use for direct connection with the computer and the 1084 chassis such as MXI or Thunderbolt. Still wondering how the NI-MAX was able to access the remote hardware under the same configuration.

[Bob_Schor]

The PXIe-1084 is a chassis that accepts a Controller (the PXIe-8821) and other PXIe cards, such as Counter/Timers, A/D, D/A, DIO, etc.  The 1084 just provides power and a backplane for its plug-in slots.  The communication is done by the Controller, typically through TCP/IP using the Ethernet connector on its face, and plugging the system onto a network on which a Host PC running LabVIEW and LabVIEW Real-Time Module resides.  You use that Host PC (as you have) to run MAX, which interrogates the local Network and "finds" the PXIe system, providing the API for you to interact with the hardware plugged into the 1084 chassis.

Note that how your PC connect to the TCP/IP network that includes your PXIe Chassis could, in fact, involve a Thunderbolt or USB-C connector, but it still needs to "talk TCP/IP" to communicate with your Controller.

Bob Schor

[rolfk]

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@bigbird49 wrote:

Still wondering how the NI-MAX was able to access the remote hardware under the same configuration.

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NI MAX uses the NI System Config API to query for hardware resources. This API does have remote support so your NI MAX on the host computer can see the hardware in your PXI chassis. But in order to use that hardware you need to use the according API that works with this hardware and NI DAQmx explicitly has no remote target support. It is a local hardware API only. NI VISA does support remote access, but that doesn't help as NI DAQmx is not built on top of NI VISA but rather has its own low level hardware access API. (It couldn't support high speed data acquisition operations otherwise).