I have two pieces of equipment that are identical in settings, yet one has a cycle time approximately 17% longer than the other. Despite confirming that all gantry speeds and permissive steps for sequences are the same between the two, they should ideally be running at the same cycle time. Both machines have the same Task configuration settings - Period = 100ms, Priority = 3, Watchdog = 500. However, one machine is experiencing a significant increase in task overlap count, reaching 2000 within a 5-minute span. When comparing the Max scan times under the Monitor Tab, the slower machine has a 17% higher max scan time than the faster one. On further investigation, adding up all the max scan times for individual programs in the task reveals that both machines have a total of approximately 15ms. The question remains: where should I focus my attention to identify the root cause of the slowdown in this task?
If you're looking for key indicators in Logix programming, keep an eye out for JMP or FOR instructions, CPS, FAL in "all" mode, and file/shift instructions. Logix doesn't include "blocking" or "wait" instructions, so identifying looping, long-executing instructions, or large AOIs like those found in PlantPAx can help pinpoint issues. Additionally, large arrays in your program may also be a red flag when troubleshooting.
When higher-priority tasks or movements are introduced, they can cause interruptions and delays to your scheduled activities. It is important to avoid having any additional tasks with identical priorities to prevent further disruptions.
According to Contr_Conn, higher priority tasks or motions may interrupt and delay your periodic tasks. It is important to ensure that there are no additional tasks with the same priority level. It has been noted that there is another task with a higher priority and a period of 7ms. Despite this, the equipment has been operating in this manner for years without any clear indication of what may have caused the slowdown. Pointer should be given to any potential changes that could have led to this issue.
When comparing the RPIs of devices, there may or may not be a noticeable impact. This comparison could help in determining the best device for your needs.
I am concerned about the overlap of tasks, which can lead to increased scan time for programs and potential watchdog faults. It is crucial to avoid any task overlaps, especially to prevent a rapid increase in them. To address this issue, I will thoroughly examine JMP and JSR instructions to understand their flow. Does a JMP instruction backtrack in the logic, requiring code rescanning? Is the JSR instruction being called multiple times in a single scan? Are there multiple JSRs for a single routine? Is there a FOR-NEXT loop that may cause looping? Any potential causes of looping will be closely examined.
Considering everything you've mentioned, the issue may not be entirely software-related. It's possible you're dealing with hardware inconsistencies or wear and tear. Identical setups on different equipment can yield different results if physical components are not functioning equally. Conduct a thorough hardware examination, check for potential blockages, friction points, overheating components, etc. If everything checks out, look into running a software diagnostic to spot potential lines of code causing this discrepancy. It could also be beneficial to observe if the problem persists at different load levels. Sometimes machines behave differently depending on the load and usage intensity.
While it's great that you've checked the configuration settings between the two machines, the identical settings and scan timings suggest that your machine's hardware or external factors might be causing the slowdown. There could be a few things happening. For starters, check the machine's general physical health - this includes regular and thorough inspection of all mechanical components for possible wear or damage. Additionally, environmental conditions like temperature or humidity can significantly affect machine performance. Lastly, it could also be a firmware issue, perhaps one machine has an older version that's causing the slowdown. Consider updating the firmware if possible or liaise with your equipment provider for more dedicated support.
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Answer: Answer: The discrepancy in cycle times could be due to factors such as task overlap count, differences in max scan times, or other program-specific settings affecting the execution speed.
Answer: Answer: To identify the root cause of the slowdown, you may need to focus on analyzing factors such as task configuration settings, max scan times for individual programs, permissive steps for sequences, and any differences in gantry speeds between the machines.
Answer: Answer: Task overlap count can impact the performance of machines by affecting the execution efficiency of tasks. A significant increase in task overlap count may lead to slower cycle times and performance issues in Studio 5000 L83E machines.
Answer: Answer: To troubleshoot differences in max scan times, you can compare the max scan times under the Monitor Tab for both machines and analyze the individual program max scan times to identify any discrepancies that may be contributing to the slowdown.
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