Hello there! I am an Ignition engineer specializing in Manufacturing Execution Systems (MES) and Supervisory Control and Data Acquisition (SCADA). I am currently collaborating with controls engineers to resolve an issue with the "Data_Ready" bits on multiple Mitsubishi Q-Series PLCs fluctuating between 0 and 1 during the timeframe of 12:00am to 1:00am. This irregularity is causing unnecessary data to be recorded in our historian system. Interestingly, there are no personnel present in the facility from 5pm to 6am, which makes it puzzling as to why this is occurring. While I am not particularly knowledgeable in MELSEC, the controls team has assured me that there are no obvious programming errors that could explain this behavior. I would greatly appreciate any insights or suggestions on how to troubleshoot and resolve this issue.
The provided information lacks clarity in terms of whether the bits read from the PLCs are set when data needs to be logged. Assuming they are, it seems likely that the PLCs are sending those bits. To investigate further, it is necessary to monitor the tags in both the SCADA system and PLCs to identify the source of the problem when it occurs. The time frame from 12am to 1am raises suspicions, particularly considering that 12am equates to 00:00. This could potentially be the trigger. With such limited details, it is akin to diagnosing a car rattle without being able to hear or drive the vehicle.
Hey there! That sounds like quite a puzzling issue, especially with no one around during that timeframe. One thing to consider might be checking for any automated scripts or scheduled tasks that could inadvertently trigger the Data_Ready bits. Additionally, have you looked into potential interference from other equipment that might be running on a similar schedule? Sometimes noise on the power supply or shared networks can cause erratic behaviors. It might be worth reviewing any logs or events around that time to see if anything out of the ordinary pops up! Good luck, and I hope you find a resolution soon!
Hi there! That sounds like a tricky issue you're dealing with. One thing to consider is checking if there are any scheduled tasks or routines in the PLC that might be executing during that timeframe, even if no one is present. It could also be worth investigating any interference from external sources, like network issues or power fluctuations, that could be impacting the PLC's digital signals. Additionally, a deep dive into the historian's setups or the conditions under which data is being logged might reveal something unexpected. Have you thought about capturing the PLC's state logs during that time to see if any other events correlate with the fluctuations? Good luck!
It sounds like a tricky situation! Since there's no one on-site during those hours, you might want to investigate if there's any scheduled maintenance or automatic processes running at that time that could inadvertently trigger those bits. Additionally, check if the PLC's internal clock is accurate; sometimes time drift or misconfigured time settings can lead to unexpected behavior. Monitoring noise or electrical interference during that timeframe could also provide clues, as fluctuations could be caused by unrelated machinery starting up or environmental factors. Good luck with the troubleshooting!
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Answer: - The fluctuation of the "Data_Ready" bits during this specific timeframe is causing unnecessary data recording in the historian system. The issue is puzzling as there are no personnel present in the facility during that time.
Answer: - Despite no obvious programming errors identified by the controls team, the fluctuation issue persists. This situation raises the need for further troubleshooting to pinpoint the root cause.
Answer: - Collaboration between Ignition engineers specializing in MES/SCADA systems and controls engineers is ongoing to address the issue. Any insights or suggestions from experienced professionals in Mitsubishi MELSEC PLCs would be greatly appreciated to help resolve the problem.
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