Finding IP address of Micro820 PLC

[dannytaki]

Having an issue connecting to my Micro820 PLC. I don't have an IP Explorer and I know its MAC Address is 5C:88:168:E6:65. I'm connected to the PLC directly with an ethernet cable from a ethernet dongle connected to my Labtop on Wifi. Running 'ipconfig' in command line oupuputs

Ethernet adapter Ethernet 3:

Connection-specific DNS Suffix . :
Link-local IPv6 Address . . . . . : fe80::1997:ab2d:9976:844e%11
Autoconfiguration IPv4 Address. . : 169.254.62.9
Subnet Mask . . . . . . . . . . . : 255.255.0.0
Default Gateway . . . . . . . . . :

Wireless LAN adapter Wi-Fi:

Connection-specific DNS Suffix . : localdomain
Link-local IPv6 Address . . . . . : fe80::6549:dfd:2a18:ee40%20
IPv4 Address. . . . . . . . . . . : 192.168.0.248
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1

Ethernet adapter Bluetooth Network Connection:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix

Wireshark Data capture on Ethernet 3 shows a Rockwell source broadcasting a message:

No devices are showing up in CCW when I try to connect to the PLC:
https://imgur.com/a/R4uXzsh

How do I connect to the PLC just built an entire trainer really excited to test it lol

https://imgur.com/a/g0XWd7T

 

[KuulKuum]

If the PLC is an out of the box configuration, then try following this procedure from RA.

https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/546239/loc/en_US#__highlight

 

[dannytaki]

Unfortunately that didn't work still wasn't able to detect the PLC in RSLinx.

Here was the wireshark data capture:
https://imgur.com/a/aS6mOwU

BootP:
https://imgur.com/a/OpbE3ue

 

[joseph_e2]

So, it looks like BOOTP utility is picking up DHCP requests from your laptop. Is the PLC's MAC ID ~E6:65? If so, then it's looking for someone at 192.168.8.60, which implies that it's on the same subnet, 192.168.8.something. I would now use the Zenmap GUI for NMap to do a ping scan of that subnet. That should locate the PLC if it already has an IP address.
Your PC has the IP address 169.254.62.9 on its wired connection, which tells me it's configured for DHCP but didn't get an IP address. That's the address range Windows uses when it chooses a random address for itself after DHCP fails. I would reconfigure the wired NIC to a static address, maybe 192.168.8.1 since that's generally reserved for a gateway device and plug it directly into the PLC's port. Then do a ping scan with NMap.


edit to add: I'm definitely not a networking expert, so I'm probably overlooking something obvious, but that's where I would start.

 

[KirkC]

It looks like your laptop does not have an IP address assigned to the Ethernet port. Wifi does not have anything to do with this.

Assign you laptop's Ethernet port an IP address (e.q. 192.168.1.10). Use the configmefirst.txt file on the SD card to give your PLC an address (e.g. 192.168.1.11).

See BLFTech's procedure here:

https://www.plctalk.net/qanda/showthread.php?t=122526

 

[drbitboy]

[update: smaller images]

i would reconfigure the wired nic to a static address, maybe 192.168.8.1 since that's generally reserved for a gateway device and plug it directly into the plc's port.

Step 1

• Let's say the network configuration is something like this first image.
• Specifically, the PC's and the Micro820's network interfaces are on different logical subnets
  • logical: i.e. the results of the bit-wise ANDs of their respective [IP Address, Netmask] pairs differ).
• The last section to the right shows one way to implement @joseph_e2's suggestion:
  • how to change the PC IP address manually to an address that will be in the same subnet as the Micro820

​

Step 2

• With the PC and the Micro820 on the same logical subnet, browsing (e.g. RSLinx or whatever it is now) allows the PC to find the Micro820.
  • Mind you, I thought the PLC would send out some Network Layer 2(? MAC-layer) packet that the browser would find, but whatever)
• Changing the IP of the Micro820 back to the original subnet as the PC, and then
• Downloading that configuration,
  • which includes accepting that that will temporarily put the Micro820 and the PC on separate logical subnets again,
  • and which in my case configured the Micro820 to get its IP address via DHCP,
• will set the Micro820 up to connect when the PC is back on its original subnet

​

Step 3

• Final image below
• The Micro820 picked up an IP address of 192.168.0.242/23 = 192.168.0.242/255.255.254.0 from my DHCP server,
• An the PC, back at 192.168.0.193/23 = 192.168.0.193/255.255.254.0, is on the same logical subnet as the Micro820,
• So the PC browser now finds the Micro820.
• and you can download programs to it, put it in online mode, and do all sorts of interesting things.

​