Hello everyone! I am currently using 3 servos for the X, Y, and Z axis, controlled by a Kinetix 5500 system. Within Studio 5000, there is a Predefined tag in AXIS_CIP_DRIVE known as "DCBusUpStatus." This tag helps us determine if the servo has lost power (400V) by setting off an alarm. According to Rockwell literature, the DCBusUpStatus bit is set when the DC Bus has reached its operational voltage level. We utilize an XIO function to trigger an alarm (OTE) when the DC Bus is not charged up (bit set to 0). I have noticed several alarms in the history where this bit was set to 0, even when the DC Bus voltage was at a normal 550V level. I attempted to implement a 500ms delay timer, but the issue persisted. Upon further monitoring, I observed that the voltage sometimes drops to 500V without triggering an alarm, despite the DCBusUpStatus remaining ON. As the alarm is self-resetting (OTE), the system continues to operate without any major disruptions. I am curious about the potential causes of this issue. Can you provide any insights into this situation?
Furthermore, I've observed that it enters a pre-charge phase lasting for 6 seconds before coming to a halt, and then resumes running.
I regularly utilize DCBusUpStatus to monitor for lockouts in my system. If this status bit ever turns false, my program immediately halts all motion attempts. I can assure you that my servos rarely encounter a false DCBusUpStatus unless they are powered off. Given your recent feedback, it appears that there may be an issue with the servo drive.
The Direct Current (DC) bus voltage fluctuates between a minimum of 543V at rest and a maximum of 785V in motion, across all three axes. Recently, an alarm was triggered at 559V, indicating that the voltage is not below the threshold for undervoltage. Additionally, the CIP_Axis_State code 16#0001 was also recorded.
I've come to understand that this issue only occurs when the axis is stationary. It pauses for a moment before resuming in a straightened pre-charge state.
It sounds like you're dealing with a tricky situation there! Since the DCBusUpStatus is supposed to indicate the operational status of the DC Bus, it's possible that there’s a slight delay or noise in the signal that prevents the alarm from triggering correctly when the voltage fluctuates. You might want to check if there are any settings in the Kinetix 5500 that pertain to the sensitivity or response thresholds for that status signal. Another aspect to consider is the potential for electrical interference affecting your readings. Sometimes adding a simple debounce logic or adjusting your timing could help stabilize the readings you're getting. Have you tried logging the actual voltage levels alongside the status to see if there's a pattern with those fluctuations?
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Answer: - The "DCBusUpStatus" tag helps determine if the servo has lost power (400V) by setting off an alarm when the DC Bus has reached its operational voltage level.
Answer: - There could be various reasons for this issue, such as fluctuations in voltage levels or potential delays in the monitoring system triggering the alarm.
Answer: - Implementing a delay timer can help address false alarms by allowing for temporary voltage fluctuations without triggering the alarm immediately.
Answer: - This issue could be caused by factors such as sensor inaccuracies, intermittent power supply issues, or communication errors between the monitoring system and the servo controller.
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