I own a MicroLogix 1200 PLC with 8 inputs and 16 outputs. Every six months to a year, I encounter a fault where the system fails to recognize one of the expansion modules. By clearing the error and resetting the controller's power, the issue is resolved. I suspect that by setting something in the processor, possibly S:1/8, the fault can be cleared with a power cycle. This PLC was recently relocated to a different facility with a new program, and after running smoothly for a year, it has encountered another fault. Can setting S:1/8 help clear the fault upon power cycling? Thank you.
I believe I previously utilized this forum to address a similar issue years ago. Do I need to set S:1/8 & S:1/15 to 1 in order to successfully clear a fault on power cycle?
Focus more on preventing faults from happening rather than solely on fixing them after they occur. If you're experiencing issues with an expansion module, it could be due to a physical connection problem caused by dirty contacts. This is a common issue with plug-in modules on ControlLogix, CompactLogix, and similar systems. Try reseating the modules and using a specialized contact cleaner spray to ensure proper connections. Additionally, consider implementing controlled heating in the panel to prevent it from reaching dew point. Keep panel enclosures closed when not in use to minimize the risk of issues. Remember, it's always better to prevent faults than to rely on temporary fixes.
After relocating the processor to a new facility, I realigned the cables connecting the PLC to the Expansion modules (1762 modules). It seems that the 3 modules currently in use are different from those at the previous location. The issue possibly lies in the PLC side connection. This fault has unexpectedly appeared after a year at the current facility. Consider replacing the ML1200 with a ML1400 to address the issue effectively.
While it's true that S:1/8 can be used to help clear certain minor faults upon a power cycle in a MicroLogix 1200 PLC, it might not be a comprehensive solution for your issue. Your issue seems to be a recurring one and it might be due to something more complex. Reasons could be anything - from hardware response timeouts, faulty wiring, or even electromagnetic interference. The relocation could also have created some unseen issues. I suggest checking your user manual or reaching out to the product's customer service for an accurate diagnosis. Also, make sure your expansion modules are secure, in good condition, and are communicating with the controller without hindrance.
It sounds like you're dealing with a persistent and tricky issue. It's true that setting S:1/8 will clear a major fault and allow for a power cycle. However, given the recurring nature of the problem, it might be wise to investigate the root cause of these faults. Temperature fluctuations, dirty power or noise on your input lines could also contribute to such intermittent issues. It might be beneficial to use some sort of PLC diagnostic tool to properly identify the problem, rather than just resorting to clearing the fault each time it arises.
It sounds like you’re dealing with a frustrating issue, especially after a year of smooth operation! Setting S:1/8 corresponds to the fault handling for the system, but it might not directly resolve the expansion module recognition problem you’re experiencing. It’s worth trying to see if it helps, but I would also suggest checking the connections of the expansion module and reviewing your program logic to ensure it’s not related to a specific input/output situation. Additionally, considering environmental factors in the new facility—like power fluctuations—could provide some insights into the repeated faults. Good luck!
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Answer: Answer: The issue could be related to various factors such as wiring connections, communication settings, or module compatibility. Regular maintenance and troubleshooting can help identify the root cause of the problem.
Answer: Answer: You can begin troubleshooting by checking the wiring connections, ensuring compatibility with the PLC model, verifying communication settings, and examining the configuration of the expansion modules in the program.
Answer: Answer: While power cycling the controller may temporarily resolve the recognition issue, it is important to investigate the underlying cause to prevent future occurrences. Consider checking the configuration settings and conducting a thorough inspection of the system.
Answer: Answer: Setting S:1/8 in the processor may have an impact on fault clearing behavior during power cycling. It is advisable to consult the PLC's documentation or contact the manufacturer for specific details on utilizing this feature effectively.
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