Greetings. We are currently facing a frustrating issue with our PLC system. We have one main PLC (1756-L85 with a 1756-en2t ethernet module) and a total of 17 Aentr nodes, consisting of SLC500 chassis and 1769 CompactLogix for remote IO. Each PLC is placed on its own VLAN network to ensure isolation. We are experiencing random dropouts specifically on the OW16 cards across remote IO racks. These dropouts occur unpredictably, affecting different racks and cards each time. The issue persists even with new replacement cards and rearranging the cards in different positions does not resolve it. The RPI is set to 40msec on all cards, though this may not impact connectivity but rather the data refresh rate of the outputs. The firmware V35 is running on the L85 PLC. We have already replaced all cabling and switches to eliminate network-related issues. On the EN2T web page, we can track the dropped cards by their new bridge connection uptime after restoration. Any insights or suggestions would be greatly appreciated. It is important to note that I am not a professional PLC engineer, but I have been self-teaching in order to troubleshoot and solve this issue.
Although the link I will share may not be directly relevant to your individual situation, it is still worth considering. My experience involved an issue with SLC RIO from a PLC-5, which took me a significant amount of time to diagnose. This problem is etched in my memory and comes to mind whenever I come across discussions about card faults related to a 1746-OW16.PLC5-SLC IO Scanner Fault. I encountered a situation where my PLC5 with SLC IO experienced scanner faults labeled as "ESO" and "L03" multiple times a day. The manual indicated it was an IO parity error in slot 3. Despite replacing the scanner, IO cards, backplane, power supply, and even switching power sources, the issue persisted. Our investigations, including observing the power with a scope and even running our specialized communication cabling, did not resolve the problem. For more information on this topic, feel free to visit www.plctalk.net.
I encountered a similar issue with a local 1769-OW16, and surprisingly, the culprit was a questionable fan connected to the same 120v power source as our OW16. Despite the fan having constant power and not being controlled by the PLC, it was somehow causing connection losses. After investigating for months, we decided to replace the fan, and ever since then, we have not experienced any further issues with the card.
Thank you for your responses. I am seeking assistance in locating and adjusting settings that can enhance flexibility in the system associated with problematic output cards. Can anyone provide guidance on this issue?
It sounds like a tough predicament you're in right now. There are multiple reasons that could lead to something like this happening, but given the randomness of the dropouts, it does seem like something that might not be just hardware-related. Something you could look into is whether there's an issue with RSLinx not coping well with the flickering connection, or if there are RSLogix 5000 tasks that are overwhelming your processor. Even though you’re on a dedicated VLAN, maybe check if there’s some sort of network broadcast storm happening. Also, it could be worth investigating if there are issues with the power supply to different parts of your system, including the OW16 cards, the SLC500, and the 1769 CompactLogix. All in all, getting in contact with a PLC specialist might save you a lot of time and trouble. It's great to see the initiative on your end, though!
This sounds like a tricky problem, but it's great you're trying to solve it yourself. I'm wondering if this could be an issue with electrical noise or power fluctuations that might be affecting the OW16 cards? You might investigate the power supply or check for any electrical noise that could be causing interruptions. While you noted that firmware V35 is running, updating the PLC and cards firmware (if not at the latest one) should be considered. Also, try examining the diagnostics/buffer logs to see if there are any specific error codes or warnings that could point to the root cause of the problem. Since you mentioned you are using an Ethernet module, another potential culprit could be packet collisions or some sort of network bottleneck, even though you've replaced cabling and switches. Lastly, keep in mind this could also be a software or compatibility issue. Please update us with your progress and let us know if any of these suggestions help!
It sounds like you're really diving deep into troubleshooting this issue, and it can be such a headache dealing with those random dropouts! Given that you've already swapped cables and switches, I wonder if interference is a possibility, especially since you’re using different VLANs. Have you tried lowering the RPI settings temporarily to see if that stabilizes things? Sometimes, it might also be worth checking for any firmware updates for the EN2T module itself, as newer versions can often resolve communication bugs. Additionally, ensure that your VLAN settings aren't inadvertently causing packet loss. It might also help to monitor network traffic more closely during those dropouts to pinpoint any unusual spikes or anomalies. Don’t give up; you’re making great strides in your learning process!
It sounds like you're dealing with quite a complex set of issues! Since you've already ruled out cabling and switches, I'd recommend checking the load on your VLANs—sometimes heavy traffic can cause intermittent connectivity problems, especially with remote I/O. It might also be worth investigating the settings of your OW16 cards to ensure they are not configured in a way that would conflict with the network setup. Additionally, consider looking into possible grounding or electrical noise issues that can affect signal integrity. If all else fails, reaching out to the manufacturer’s tech support could offer more specific insights tailored to your hardware. Good luck!
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Answer: - The random dropouts on the OW16 cards could be caused by various factors such as electrical interference, configuration issues, firmware compatibility, or hardware malfunctions.
Answer: - The unpredictability of the dropouts may indicate a systemic issue affecting multiple components within the PLC system, rather than isolated problems with specific cards or racks.
Answer: - Troubleshooting steps could include checking for loose connections, verifying firmware compatibility, analyzing network traffic, monitoring error logs, and seeking assistance from professional PLC engineers for a more in-depth diagnosis.
Answer: - While adjusting the RPI setting may affect the data refresh rate of the outputs, it is unlikely to directly impact the overall connectivity between the PLC and remote IO racks. The RPI setting determines how frequently the PLC requests data from the remote IO modules.
Answer: - Possible solutions could involve conducting a thorough inspection of
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