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Micro820® and Micro850® Default IP Address

Wayne Welk2/18/2019

This Tech Files note comes from a Rockwell Automation Knowledgebase article that is open to everyone regardless of TechConnect support status. View the original Knowledgebase article here.


This Tech Files post answers how to assign an IP address to a Micro820® controller when it is new out of the box. The Micro820 does not have a USB port to connect to, so connecting to it straight out of the box may not seem possible without knowing the IP address. Upon power-up of a new Micro820, the controller will assign itself an IP address if a DHCP server is not present. The steps below discuss how this is done, and how to connect to it using the temporary IP address.


The out of box configuration for the Ethernet port is for DHCP (no BOOTP support). If a DHCP server doesn’t respond with an IP address within 15 seconds, then the controller will assign itself a random IP address (like a Windows PC). This allows someone to direct connect a PC Ethernet port to the Micro820 or 850 Ethernet port, browse for the Micro820 or Micro850 and connect using Connected Components Workbench™.

To establish communications with a controller configured to use a random default address follow this procedure:

Note: Controller must be in PROG mode and you cannot be online to apply settings change.

  1. Shutdown Connected Components Workbench and RSLinx Classic software.
  2. Open Windows Ethernet card settings and set IP configuration to: IP =, Subnet Mask =
  3. Open the RSLinx Classic software.
  4. Go to Communications –> Configure Drivers…
  5. From Available Driver Types pull down list select EtherNet/IP Driver.
  6. Add new driver by selecting OK.
  7. Configure driver to browse your local subnet’s network card.
  8. Click Apply to the settings and then hit OK.
  9. Close the Configure Drivers window.
  10. Go to Communications –> RSWho.
  11. Expand the Ethernet/IP (AB_ETHIP-1) driver created before to allow the software to scan the subnet.
  12. Right click on controller and select Module Configuration.
  13. In Module Configuration, click on Port Configuration.
  14. Set the Network Configuration Type to Static.
  15. Set the IP settings and hit the Apply then the OK button when done. Refer to ID:  QA51656 Valid IP address range for Micro800 Controllers for choosing a valid static IP address for your Micro800 controller.
  16. Change the PC’s IP settings to be on the same network as the new controller’s IP settings.


Here is a list of frequently used technotes with Micro800 controllers (valid TechConnect support may be required):