How do I find an unknown IP address?

Hello all,

So the company I'm with just got the RSLogix 5000 software so I can make some changes to an existing machine.
The Machine is running a CompactLogix and I don't know the IP address it's using.

I'm search old posts, and found this one: http://www.plctalk.net/qanda/showthread.php?t=48491&highlight=Find+IP+Address

But I can't seem to find any devices when I use RSLinx.

I currently have my computers IP address set manually (to one we use to connect to a vision camera), and my network Connections tells me I'm connected, but RSLinx shows nothing.
When I set the Computer to "Obtain an IP address automatically" Network Connections faults out and can't set an IP address.

The machine was buitd by a third party company, and they all leave at 4. I like to get online tonight, rather than wait till tomorrow.

Thanks in advance

Download Wireshark from www.wireshark.org.

Plug into the switch with the CompactLogix. Start capturing with Wireshark. Cycle power to the CompactLogix.

Type the letters "arp" into the Display Filter field in Wireshark and hit Enter. You'll see the CompactLogix broadcasting its IP address upon bootup, to confirm that there are no other devices on the LAN with that IP and to populate the MACID tables of the connected switches.

There are other threads about this; search on "Wireshark" and "ARP".

I sell a device that will do it... not sure how often you would need it so it may not be worth it

http://www.plctrainer.net/AutomationSupplies.htm

Regards
Mark

This is a ControlLogix 1756-ENBT that was set for a totally unrelated IP subnet than the one into which I plugged it:

Look@Lan is also handy for this.
ControlLogix, CompactLogix will show up as "Not Windows" (duh), by default with SNMP enabled (public), and the device part number.

Look@Lan is still available for download: http://www.lookatlan.com/download_lal.html
But they are working on a newer tool to replace it.

Did the supplier of your machine give you a copy of the program that you can open with RSLogix 5000 from the off line file as this file has the fully documented program.

If yes then the address should be available through controller properties from your off line file.

Well, I was going to write what Gil47 wrote, but will just have to say: Connect with a serial cable and look at the processor status that way.

Gil47 said:

If yes then the address should be available through controller properties from your off line file.

Click to expand...

Where is the fun in that?? we need to spend a lot of time and money doing these kind of things... or just anyone will think they can do it and we will no longer be needed