I am using a Rockwell PLC model 1769-L36ERMS and have successfully assigned it an IP address. However, each time I reboot the PLC, it loses communication with my PC and HMI. I have to constantly re-enable BootDHCP. Can anyone offer any suggestions on how to resolve this issue?
It is important to *turn off* BOOTP/DHCP when assigning a static IP address to ensure proper connectivity. This can be done using the BOOTP/DHCP tool or RSLinx Classic. Be sure to set your IP address and default gateway within the same subnet to avoid any configuration issues on the controller.
It sounds like you might be encountering issues with persistent storage of your IP address configuration. When you're configuring the IP address, are you using BOOTP/DHCP Tool? If so, try disabling BOOTP after assigning the IP address. Once this is done, the IP address should remain consistent even after a reboot. This is often overlooked, but can cause the issue you've described.
It sounds like you're dealing with a pesky issue, indeed! One thing that comes to mind is to check the battery on your PLC; it might be weak or dead, causing the PLC to lose its settings whenever power is cycled. If the battery's fine, you could look into enabling BootP permanently instead of DHCP. Remember to save the settings after you make the changes, that might be another reason for losing the configuration after a restart. Additionally, also make sure your firmware is up to date, as it might fix any unexpected bugs. Don't forget to back-up your setup before making any changes.
It seems like your PLC might not be saving the IP address to Non-Volatile Random Access Memory (NVRAM). Try saving the project to NVRAM after assigning the IP. If the issue persists, then it could be a firmware problem, so I'd recommend updating the firmware to the latest version. If that still doesn't fix the issue, it could be a failure of the underlying hardware, as persistent changes should be retained even through a power loss situation.
It sounds like you might be dealing with a common issue where the PLC does not retain its IP address after a reboot. One potential fix could be to switch off the BootP/DHCP option once you've successfully assigned your PLC an IP address. You can do this using Rockwell's BootP-DHCP tool - after assigning the IP, click on the "Disable BOOTP/DHCP" option. Also, ensure your PLC's battery isn't low, as this could cause it to lose the stored IP address. Always remember to back up your configuration to avoid reprogramming in case of power loss. Hope this helps!
It sounds like you might have a configuration issue with the network settings. Make sure to set the IP address to a static one instead of relying on BootDHCP; this will help retain the settings after a reboot. Additionally, double-check if there's a network or protocol configuration conflict that might be causing the communication loss. If you're using a DHCP server, ensure it's not reassigning the same IP that's meant for your PLC. Good luck!
It sounds like you're running into a common issue with the DHCP settings on your PLC. One potential solution would be to switch from BootDHCP to a static IP configuration if your network permits it—this way, the PLC will retain its IP address after rebooting. You can do this by accessing the controller's Ethernet configuration settings and manually entering your preferred IP address, subnet mask, and gateway details. This should help maintain consistent communication with your PC and HMI. If you still want to use DHCP, ensure your DHCP server has reserved an IP address for the PLC's MAC address to avoid it changing each time it boots.
✅ Work Order Management
✅ Asset Tracking
✅ Preventive Maintenance
✅ Inspection Report
We have received your information. We will share Schedule Demo details on your Mail Id.
Answer: 1. Why does my Rockwell PLC lose communication with my PC and HMI when rebooted? - The issue may be related to the BootDHCP setting on the PLC, which needs to be re-enabled after each reboot. 2. How can I resolve the lost communication issue with my Rockwell PLC when rebooting? - One suggestion is to check the network settings and ensure that the IP address assigned to the PLC is configured correctly. 3. Is there a way to avoid having to constantly re-enable BootDHCP on my Rockwell PLC? - You may consider configuring the PLC to retain its network settings even after a reboot, eliminating the need to re-enable BootDHCP each time.
Join hundreds of satisfied customers who have transformed their maintenance processes.
Sign up today and start optimizing your workflow.