How can I eliminate delays in one NIC when there is traffic on second NIC

[LabBard]

Using LabVIEW TCP/IP VIs, my LV application is  accessing a database though a LAN, and  through a second NIC, it is controlling an instrument.  The instrument is connected directly to the computer NIC with a cross-over cable.  I have made a permanent route for the IP address of the instrument in the IP route table.  The LAN and the instrument have different subnet numbers.  Using a packet sniffer, I don't see any traffic meant for the LAN going to the NIC connected to the instrument.  The OS of the computer is Windows XP and the NICs are PCI cards.

The message traffic to the instrument suffers from intermittent delays when there is traffic going to the LAN. 

How can I eliminate the delays?  What could be the cause of the delays?  Thanks in advance for your recommendations and suggestions.

[Paul_m6]

attach the vi

[Sputnikrent]

Hi LabBard,

Could you tell us a little more about the device that you are connected to? What you could try is to have a VI accessing the LAN, and a separate VI communicating with the instrument, and see how things play out.

Let us know how it goes!