Micrologix 1100 no IP address

Hello, I´m new to PLC, currently trying to program one (1100 micrologix) for the first time.

I was able to communicate yesterday but I didnt knew I had to disable bootp
so now I cant even comunicate

To see the IP I tried to do this from page 133 of http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1763-um001_-en-p.pdf
what appears is attached.

I believe it´s the same problems as in this thread but I dont have a serial cable to correct it. http://www.plctalk.net/qanda/showthread.php?t=105293

or this one: http://www.plctalk.net/qanda/showthread.php?t=86215

Moonshiner1 said:

I have a ml1100 that I had comms via ethernet working. I didn't know I had to disable bootp/dhcp until I already powered down. It is no longer communicating with the ab bootp server software. Does anyone one no if/how I can fix it without serial cable?

Click to expand...

but I have no router atm, I may get one later.

I tried to assign the IP with the BootP DHCP Ethernet/IP Comission Tool with no success.


Can I fix this problem with just an ethernet cable??

If you can get a network switch or CAT5 crossover cable and connect to the ML with nothing else connected, then use Wireshark to watch for the BootP request (not sure about ML's but on SLC's it only does it once at bootup)
If it shows an IP address then change the IP on the computer network adapter to match and the RSLinx should be able to connect to it.

Hello, thank you for replying, could you be a little more specific of what I have to do ,
How do I watch for the BootP request in Wiredshark? how do I use it?

You can see (but not change) the Micrologix IP on the PLC LCD Display, then connect PC and PLC using a crossover cable or using a hub or switch with normal cables, then change the PC ethernet adapter IP to another address on the same PLC subnet , for example if the PLC IP is 192.168.1.2 then put 192.168.1.3 on the PC and then RSLinx should connect successfully.

lfe said:

You can see (but not change) the Micrologix IP on the PLC LCD Display, then connect PC and PLC using a crossover cable or using a hub or switch with normal cables, then change the PC ethernet adapter IP to another address on the same PLC subnet , for example if the PLC IP is 192.168.1.2 then put 192.168.1.3 on the PC and then RSLinx should connect successfully.

Click to expand...

I used to be able to see it but since today I cant.


edit. idk why but I cant see my attached pictured, its the screen of the plc and it says : MAC/IP = 001D9CA14BAF/-.-.-.- instead of the IP

Save yourself some time and buy the serial cable. Handy for unknown IP devices or the 1000 that doesn't have ethernet.



If you didn't disable BootP then it should still be in DHCP range of 192.168.1.xxx