ethernet daq on PC with 2 adapter boards

[Ben_Engelen]

Hi,

I have a problem with daq over ethernet (cdaq chassis).

There are two boards installed in the computer, the primary board is configured to connect to company network (DHCP) and the other one is configured with a static IP adress to connect to the CDAQ enet module.

But it does not work, the cdaq chasis could not be found whenever the primary adapter is enabled.

When i disable the primary adapter everything works perfect!

I followed the procedure in the trouble shooting guide but no succes...

thx for the reply's

[krue]

Hi

I have exactly the same configuration and exactly the same problem. It works as soon as I disconnect the company network cable or disable the primary adapter. I talked to our institute's admin and he suspects that connecting the computer to a domain network causes the problem. Windows apparently changes some internal configuration params according to the network type it connects to... I'm not a computer scientist, so I'm completely stuck...

Thanks for any help

Markus

My system: cDAQ NI-9188, LabVIEW 2011, MAX 5.0.0f1, NI-DAQmx 9.3.5

[Ben_Engelen]

We didn't found a solution for the problem, instead we replaced the chasis with a USB version 😞

[Brian_A]

Hi Ben_Engelen and Krue

When both ethernet adapters are enabled are you able to get a response from pinging the cDAQ chassis? Have you tried manually adding the device to MAX using it's IP address? 

Cheers,

Brian A

R & D Product Support Engineer | WSN/Network DAQ/Academic

National Instruments 

[krue]

Hi Brian A

Thanks for your response. We can ping the DAQ, but we can't add it to MAX manually. It's also listed in the NI Network Browser, but it's not possible to connect and view/change settings... Could it be a problem with the firewall?

Cheers, Markus

[krue]

Hi Brian A

Here's another hint: MAX displays a message which refers to ni.com/info and infocode 'SettingsUnavailable'. NI System Web Server is running and TCP Port 3580 is excluded with a special firewall rule. There's a note in the firewall settings, though, saying that some settings are managed by the admin... So some settings might be overrided.

We have also just updated the firmware to v1.4.

Hope this helps

Cheers, Markus

[ThiCop]

Hello Krue,

Do you have information about the "settings" (subnet masks, IP-adress, etc.)  that are used on both ethernet ports from the pc-side and from the side of the cDAQ?

[krue]

Hi everybody

A co-worker of mine found the problem by analysing the packets from adapter 1 and 2. Apparently the cDAQ uses http to communicate with MAX. As soon as the company network is connected, all http packets are routed to the proxy server, which is connected to adapter 1. Recognising the cDAQ works with a different protocol. So the recognition works, but communication does not (while the proxy configuration is active).

Solution 1: Disable the proxy configuration system wide, and configure your browser (i.e. Firefox) to connect to the internet via proxy. This probably doesn't work with the internet explorer, because it uses system settings.

Solution 2: Add an exception to your configuration, so that windows doesn't use the proxy for certain IPs.

It seems to work perfectly now

Cheers and good luck

Markus

[ThiCop]

Hello Markus,

Thanks for the feedback!

Some other info that might be interesting:

- In general Detection of devices over ethernet (not only for NI) will be connectionless (eg. UDP multicast messages).

Just think about any kind of heartbeat signal to see if an instrument is still alive.

- Actual communication (eg.http) will in general be connection based.