LabVIEW + communication protocol

[kevin_khan]

Hi there,

I am currently working on a project which involves acquiring data from a cardiac mapping unit and transmitting and displaying this data on the PC.  I plan on using LabVIEW to create a GUI to dispay this data.  The system is designed to transmit 1024 ksamples/s. Currently I am looking into two different communication protocols to transmit the data to the computer and displayed in LabVIEW.  The two communication protocols under investigation are USB 2.0 high speed and Ethernet.  However I would like to have your input to know which protocol would be best suited to interface with LabVIEW.  I would like to know  which would be easier to implment to interface with LabVIEW.  I would like to know which one of the two communication protocols outlined which would be the best to meet design requirements of this project. 

I should also note that I have no experience programming either USB or Ethernet.

[nyc_(is_out_of_here)]

Ethernet

[Mark_Ramsdale]

Hi,

What protocol is the instrument designed to use? Are there LabVIEW drivers for this instrument?

Generally speaking, you should not have to program the protocol, just use the drivers and they should take care of the protocol.

There are factors to consider like how long a cable will you be using, USB has limits there.  Best to research the issues surround the transfer rate and distance, etc... 

From the LabVIEW POV you would probably use VISA to communicate, and it would manage your protocols.  This depends on the drivers you may or may not have and the instrument.

Well, just a starting point for your question.

[crossrulz]

I second the ethernet.  More bandwidth and there are plenty of examples of how to use it.

[nyc_(is_out_of_here)]

I got the impression they are designing their own interface hardware.

If not then their decision has been made for them by whatever interface(s) are available on the cardiac machine.

[kevin_khan]

Thats right we are designing our own hardware

[Mark_Yedinak]

I would go with Ethernet. You would then have the option (potentially) of going wired or wireless. With Ethernet you can have you monitor in one location and the GUI at another. This is not very easy to accomplish using USB. In addition, if you go with UDP (provided you can drop a packet occassionally) you can also broadcast the data so you can support multiple GUIs or logging devices at one time.

[JW-JnJ]

If you're designing the transmitting hardware, it might get interesting.

For USB, the ease depends on the hardware implimentation. If you're using a UART->USB like the FTDI on the Arduino, then it's really easy. Install the drivers and use VISA to communicate with the virtual serial port. If you're using raw USB protocals, you're beyond my expertise, but I imagine it'll involve writing drivers on the LabVIEW side.

I imagine ethernet will be fairly annoying on the hardware side. However, it will be only slightly more complex than serial on the LabVIEW side. You gain all of the benifits mentioned above.

If you're approaching this from a pure LabVIEW point of view. I would vote Ethernet. Lots of gain for little effort.

If you're considering the hardware impacts... that's a tough one.

[crossrulz]

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@JW-L3CE wrote:

If you're designing the transmitting hardware, it might get interesting.

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Keep in mind that JW is also still bitter with the program he is currently working.  The VHDL people don't know ethernet and decided to write their own code.  JW got stuck in the middle of it.  I avoided that portion of the project like the plague.  If your people know ethernet protocols, you shouldn't have the issues we did.

[Nathan-P]

The following Discussion Forum post is on how to get started communicating with LabVIEW through a USB device:

https://forums.ni.com/t5/LabVIEW/Can-Labview-2009-communicate-via-an-USB-port-to-a-custom-PCB/td-p/1...

The following links have more information on developing a LabVIEW program with TCP/IP and UDP:

https://www.ni.com/docs/en-US/bundle/labview/page/using-labview-with-tcpip-and-udp.html

https://forums.ni.com/t5/Developer-Center-Resources/Inter-Application-Communication-TCP/ta-p/3523043