Hello, everyone. I need your expertise to troubleshoot why my FX3U-48MR/ES main PLC keeps encountering errors upon restart. Due to the password protection set by the OEM, I am unable to access or monitor the PLC program. The OEM supplied me with the program file solely for uploading to the PLC. The only solution I have found to remove the errors is by reuploading the program each time, but the issue persists after every restart. Can anyone provide insights on how to fix this recurring problem with the PLC?
Are you using any specific software for re-uploading? If you still have the original program file, you can easily remove the password, reset the PLC, and then re-upload the program.
Ron S inquired about the software being used for re-uploading the program. If you have the original program file, it is possible to remove the password and clear the PLC before re-installing the program. Please note that I am not directly re-uploading the program to the Main PLC. Instead, I am uploading it via a HMI (Beijer X2 Pro 7) using a USB memory stick and following the steps provided by the OEM. Attached are the instructions for reference. I am facing challenges in converting the file for compatibility with GX Developer. You can find more information on my file compatibility issue in another thread.
It is possible that the issue lies in a *.fx file, such as a divide by 0 error. It is uncertain if it is possible to go online with a secured PLC, but if access is granted, the diagnostics will indicate the error, with a common occurrence being a divide by 0 error. This could be due to a D register being mistakenly set to 0 and used in a divide function, or an issue with indirect addressing where a variable is placed outside the address space. Following the instructions in the document to record HMI settings, restore them, and reboot may resolve the issue. When downloading the code to the PLC, the registers may reset to zero, potentially causing the problem. Make sure to set the PLC to stop mode before downloading the file, re-enter the variables from the HMI screen, and then switch to run mode. This may help resolve any divide by zero or indirect addressing errors, but the exact issue remains unknown.
While downloading the program through the HMI works fine, errors occur upon powering down. Parky suggests that a divide-by-zero error is likely the issue. It is probable that a non-retentive register in the PLC program resets to 0 after power loss, causing the error. However, the use of USB resets the correct value back.
I am curious if a flat battery could be causing issues with a downloaded .fx file. While the file runs fine when the device is switched from stop to run without powering down, there seems to be a problem after a power cycle. Could the loss of data from a low battery be causing this issue? I would expect the battery indicator to signal if this were the case. Does the device boot successfully when reloaded, but only fail after a power cycle?
It sounds really frustrating dealing with that issue, especially being locked out of the programming. Have you checked if there's a specific error code when the PLC restarts? Sometimes, those codes can give clues about what's going wrong. Also, it might help to look into whether there's an option for factory resetting the unit, or see if the OEM can provide any support documentation or a more in-depth troubleshooting guide. If the problem continues, it might be worth contacting them for assistance, especially since they hold the program password. Good luck!
It sounds like you’re in a tough spot with the password protection and the recurring errors. Since reuploading the program temporarily solves the issue, it might suggest that there’s a configuration or memory problem that’s not being saved correctly. Have you checked the PLC's battery? It’s possible that if it’s low or failing, it might not be retaining the necessary data upon restart. Additionally, if you can, try reaching out to the OEM for support; they may provide insights or an updated version of the program that could address these startup errors. Good luck!
It sounds like you're in a tough spot with that PLC! Have you checked if there's an issue with the power supply stability or wiring connections? Sometimes, erratic behavior can stem from inadequate power during startup. If possible, try to gather any error codes or indications that might give clues. When you re-upload the program, are you ensuring it's fully synchronized before restart? It might also help to reach out to the OEM for more guidance; they may have encountered this issue before or suggest a way to reset the password for troubleshooting. Good luck!
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Answer: 1. How can I troubleshoot recurring errors on my FX3U-48MR/ES main PLC upon restart? - To troubleshoot recurring errors on your PLC, ensure that the program file provided by the OEM is uploaded correctly. If errors persist, consider checking for any hardware issues or compatibility issues with the program file.
Answer: - If you are unable to access or monitor the PLC program due to password protection, reach out to the OEM for assistance in obtaining access. Alternatively, consider consulting with a professional or service provider who can help you navigate the password protection.
Answer: - Reuploading the program may temporarily solve the errors as it refreshes the system and may correct any inconsistencies or errors in the program execution. However, if the issue persists after every restart, there may be underlying issues that need to be addressed.
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