VISA TCP/IP RESOURCE (LAN Connection) vs. USB?

[rkmadse]

I'm wondering if I shold expand the number of USB ports I have on my workstation or add a USB hub, or if TCP/IP Lan connections can be just as fast as the USB connections? At first attempt it seems like when using the LAN connected insturment that the response is much slower than when it's USB connected, but my workstation has sufficient TCP/IP ports and not enough USB connections.

Thanks,

Kellen

[JÞB]

You should be usuing a externally powered USB Hub already!  Depending on the internal power supply is asking for trouble.  Stick with the USB and buy a quality Hub. 

[crossrulz · Accepted solution]

Personally, I do not trust USB.  I have had too many issues with it.  Cables randomly edge out.  Cables get moved around and therefore it is "new".  In a dedicated test rack that just sits there, it is probably fine. But you should definately be using a good externally powered hub.

But I prefer to go the LAN route, especially if you have LXI compliant instruments.  There is just something about connecting to your instrument through a web browser to make sure it is working properly.  And all you need is a good Ethernet hub and you can connect a ton of instruments.  If you do go this route, have the instruments be on their own little network with fixed IP addresses.  It will make your life a lot simpler.  If you need the computer to be on a company network, that is fine.  Just make sure you have 2 Ethernet ports.

Yes, USB has a lower latency.  When streaming data, LAN can play catchup (at least with Gigabit).  There are pros and cons to both options.

[rkmadse]

Thanks for the feedback, I appreciate it! In my test rack I'll be constantly swtiching each instrument through a switch matrix and taking measurements at the output. So only one instrument will be taking a measurement at a time. I worry that switching back and forth between them might bring out the bad latency in LAN, and I don't take enough continuous samples for it to catch up. I appreciate the help.