remote target location over Ethernet

[toutiao]

Dear Friends,

Every time we get a new compact fieldpoint, we can connect it to Ethernet  and power it up then being able to locate it from another PC from MAX. There is a DIP switch we need to flip (the 8th one, I believe).

I wonder how does MAX locate the cFP, without prior knowledge of the IP address, which could vary from network to network. I guess it is done through MAC address and ARP searching. But how does MAX know which MAC address to look for?

I have no intention to steal NI trade secret. I had a feeling this technology must be public available. I just need someone pointing me to the right direction.

Many thanks in advance!
ZJ

[RavensFan]

I believe MAX broadcasts a message, either UDP or TCP to all IP's on the subnet.  The compact Fieldpoint it set to respond to that message.  MAX just waits for the response.

[toutiao]

Ravens Fan,

Many thanks!

Let me try to understand you here: you are implying that although the cFP is NOT-preconfigured, whenever we flip the right DIP switch and power it on, there must be some firmware algorithm keep parsing that data buffer of the Ethernet port (which also implies the firmware have some sort of driver for the Ethernet port). Whenever the program parsed out a predefined "token", broadcasted by the PC running MAX (only through UDP, right? since the host doesn't know the IP address of the traget), it will respond in to the host, with it MAC address. Then the host will be able to locate the cFP with its MAC address to proceed with configurations.

If you have time, tell me what you think.

ZJ

[RavensFan]

To the best of my knowledge, that is correct.  Someone else may have a better grasp of the details.

I guess it is UDP as technically the target has no IP address since it is 0.0.0.0.