Accessing multiple subnets with CRIO

[lisam88]

Is it possible for a cRIO to access multiple subnets and how can this be achieved?

[MarkCG]

Well you can use the secondary ethernet port and connect that to a different subnet yes. You can configure how that port works in MAX. So if you have multiple devices that are ethernet controlled you can put them along with the cRIO on their own subnet with a router. The cRIO can be connected to the office / plant internet through the primary ethernet port. That way no one except the cRIO can access those devices.

[lisam88]

Hi Mark,

Thanks for your response.

So where devices with different subnets (per VLAN) are connected to an ethernet switch, the cRIO would be connected to the switch via a router - with an ethernet port per subnet?

Do you know if it is possible to have multiple VLANs on one subnet, so that a router is not required?

[lisam88]

or does the cRIO require a different interface for each VLAN? So that it would require one VLAN per subnet..?

[lisam88]

I am working with 3 VLANs. Is this even possible on a dual port controller?

[MarkCG]

I am afraid I don't know much about VLANs. Basically what I have done is have router with say a subnet of 192.168.1.xxx connected to the secondary ethernet port. Then I put my devices to a router, along with the cRIO, settign static IPs for everything. Then I can address the devices from the cRIO with their static IP on that subnet like 192.168.1.10 for a power controller, 192.168.1.11 for an oscilloscope, and so on. Meanwhile the cRIO also connects on the shop network  via the primary port, which is setup as a different subnet, say 10.1.1.xxx. So the cRIO connects to the HMI via this network-- the user interface program can control the cRIO from anywhere in the shop.

Don't know if that helps, hopefully someone can better answer your question

[lisam88]

That makes sense. NI said it's not possible to tag VLANs on a cRIO port, so in that case I would require a port per VLAN. As it's dual port it would need a ethernet switch module, which does not interact with the FPGA. I think I will try to think of other solutions instead. I appreciate your time - thanks!

[BradM]

Hi there lisam88,

I meant to reply earlier, my appologies. From a quick poking around in the kernel source, it seems that the kernel configuration is there for the 8021q module, and that the hardware that I am aware of (for both x64 and Zynq targets) supports VLAN tagging, so it seems that it should work. I have not actually tried it, full disclosure.

[lisam88]

Hi BradM,

Many thanks for your message.

Do you know if vlan tagging is compatible with the cRIO-9035?

[BradM]

I believe that the 903x series uses the igb driver atop the i210 ethernet controller, both of which support VLAN 802.1Q. So, yes, it should work. Sorry to be noncommital but I don't really readily have the hardware in front of me nor the time or network configuration to test that out and give you an authoritative answer