Can I use 2 ethernet cards in 1 PC with LabView?

[Harlan]

I have a number of standalone PCs which each have a NIC for communication with other hardware. I wish to network these machines together with an additional NIC.
NatInst says: "
LabVIEW will only recognize one network card on your system. To find out
which card LabVIEW will use (when dealing with the TCP/IP VIs or any other
networking functionality in LabVIEW), you need to go to the Network
Properties (right-click on Network Neighborhood and choose "Properties"),
and you'll notice a TCP/IP entry for each of your network cards. Go to the
Properties of the TCP/IP entries, and whichever one has "Set this protocol
to be the default protocol" checked under the "Advanced" tab will be the
one that LabVIEW uses.

I hope this clears up the situation. R&D is aware that customers wish to
use multiple network cards in LabVIEW, and we may see this feature added in
a future version.

Have a good weekend.

Sincerely

Darren Nattinger
National Instruments
http://www.ni.com/support

But in the developer's exchange, I read"
Hello All

some one mailed me a message requiring a problem we had a while ago about
two Ethernet cards on one PC. Unfortunately I accidentally deleted the
message before responding to it, so if I post the answer here maybe they
will see it.

We got two Ethernet cards to work with LabVIEW by giving them different
address. I.E. Card 1 had address 123.456.FFF.001 and card two had
234.567.FFF.001. Card one was connected to the network and card 2 was
connected to the unit we wanted to test. We think that LabVIEW uses the
address to determine which card is being used. Anything connected to card 1
must be on the same domain in order for it to work I.E. 123.456.XXX.XXX
where X = any hex number from 1 to F )( the same for card 2 ) We didn't
test this theory, but our system is working and it is the best explanation I
can come up with.

Chuck Stewart"

So who is right?

thanks, Harlan McKay

[Dennis_Knutson]

We use 2 NICs all the time. One NIC is set to get it's ip from a DHCP server and we specify the ip of the second. We've never had a problem as long as the second card's domain and subnet is different from the company network.

[Darren]

Hello,

I figured I would post a correction to my previous answer to clear up the confusion. Apparently it is possible to use multiple network cards with LabVIEW...I had been told otherwise by one of my colleagues a few years ago and had assumed his information was accurate until I saw this Developer Exchange thread.

So to clarify...according to other customers' posts on the Developer Exchange, it is indeed possible to use multiple network cards with LabVIEW. I have never tried it, however.

Darren N.

[TRLJr]

I have a problem similar to but not exactly like Harlan's.  I have two PC's each w/a network card that gets its address from the Corporate server and a NIC w/a hard coded address for use w/Labview on a separate network.  The addresses on each PC are very carefully kept separate.  The differance is that one PC has LV and the other only has the Run-time engine.  My OS is Win2K on both.  My problem is that when I run a server on the LV PC and compile and run a client on the non-LV PC, the server never sees the client trying to connect.   I have not yet tried the reverse.  I can successfully Ping the cards across the private network.  My question is, how do I know that the client is trying to communicate through the private card like it is supposed to and not through the corporate card?

Thank you,

Tom

[RobCole]

From the help file for Create Listener.vi:
net address specifies on which network address to listen. Specifying an address is useful if you have more than one network card, such as two Ethernet cards, and want to listen only on the card with the specified address. If you do not specify a network address, LabVIEW listens on all network addresses.

We use multiple network cards frequently and have never had a problem. We set up a listener on one computer with no network address specified and then a client on another computer that specifically states to connect to X address on Y port.

The LabVIEW client/server examples let you specify address and port. I would give them a try and see if you can get communication working.

     Rob

[unclebump]

You can also multihome an ethernet card and give a single card up to ten ip addresses.

[Sirin]

Sorry to bump such an old topic, but I am still a little confused after reading all of the info here. I'm going to need to use 2 ethernet cards, both running TCP/IP servers. I also would like to use the Datasocket server to serve information to one of the networks.

I don't see anything in the create listener VI or in the other TCP/IP server VIs that allows me to tell which NIC or IP address to link the server to. When I create a server on a computer with multiple NIC cards, does this make the server listen on both IP addresses? Or is it not possible to use 2 NIC cards with LV 6.1 (the version I am using)?

I'm also curious about the ramifications with Datasocket server. Will it accept data requests from either network card, or will it only respond from one of the IP addresses?

Thanks for your help.

[JLS]

Hello,

I have read the thread above, and it sounds like you'll need to do a bit of experimentation in your 6.1 environment to see if it will work.  If you have problems, posting the errors and/or problem descriptions may give us hints about what's going wrong.  Be sure to read the thread since there is some good information there, and I hope you're able to get you required setup working!

Best Regards,

JLS

Message Edited by JLS on 04-27-2006 04:19 PM