Our Powerflex 525 drives are configured for remote operation from a PLC via a network connection. However, in the event of network loss, we want the ability to switch to local operation using the local display panel. Despite our intention to run in local mode when the network is down, we are encountering a fault. This fault may be prevented by adjusting a parameter called 'comm loss action' (C125:0), where options include FAULT, Coast Stop, Stop, and Continue LAST. By setting the 'comm loss action' parameter to a value other than 0, we hope to avoid encountering a fault that hinders local operation. It seems that the system was not thoroughly tested for network disconnection scenarios, as we are unable to seamlessly switch to local operation when needed.
When I am observing, I typically set the parameter to 3: Continue Last on the drive. Other parameters determine the speed reference and start/stop commands based on digital inputs. After clearing the network loss fault, do the local controls function properly?
When I'm on a monitoring drive, I usually set the parameter to 3: Continue Last. The drive also has other parameters that determine the speed reference and start/stop commands based on digital inputs. After clearing the network loss fault, do the local controls function properly? I will attempt to clear it and test it out.
When deciding on the parameter setting, it may be beneficial to consider changing it to "Continue last" unless there is a risk of no one being in close proximity to detect and take control. Ultimately, the choice between stopping or continuing should be based on safety concerns.
To enhance operator safety and efficiency, consider incorporating a selector switch on the drive for seamless control source adjustment from network to local in case of communication loss. This allows for quick and easy switching without the need for manual parameter adjustments during emergencies. While specific details may vary based on the VFD model, this practice is commonly implemented in most VFD systems.
OkiePC suggested a solution to address communication loss in VFDs by recommending adding a selector switch for quick and easy control source switching from network to local. This practice is common among most VFDs and can be easily implemented on a 525 model by configuring an Input as Source and Control select. Users can preset Control Source 2 to 2-wire and Control Speed 2 to HMI speed, allowing for seamless switching between Source 1 and 2 with just a configuration of the Input settings.
It sounds like you're on the right track by looking at the 'comm loss action' parameter. Setting it to 'Continue LAST' or 'Coast Stop' could definitely help by allowing the drive to maintain its last known state when the network is lost, which might help avoid the fault you're experiencing. It’s surprising that such network disconnection scenarios weren't fully tested, as having a robust fallback option for local operation is critical in real-world applications. Have you also checked the configuration of your local control settings? Sometimes, minor tweaks there can help improve the system's responsiveness during a switch-over.
It sounds like you've got a solid plan for handling network loss, but I agree that the lack of thorough testing for these scenarios is concerning. Setting the 'comm loss action' parameter to something other than 0 should definitely help, but make sure to test it in various conditions to see how it behaves. Sometimes, even minor firmware settings can make a big difference in how the drives respond. Have you considered checking if there are any firmware updates or support documents from the manufacturer that specifically address local operation during network loss? It could save you a lot of headaches!
It sounds like you're running into a pretty common issue with remote-to-local transitions on these drives. I've found that adjusting the 'comm loss action' parameter can make a big difference. Setting it to "Continue LAST" often helps bypass the fault and allows for more fluid switching to local operation. It might also be worth double-checking your network settings and ensuring the drive's firmware is up to date, as improvements sometimes get rolled out for precisely these types of scenarios. Don't forget to test the setup during downtime to iron out any kinks before relying on it in critical situations!
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Answer: Answer: The 'comm loss action' parameter (C125:0) in PowerFlex 525 drives allows you to define the drive's behavior in case of network disconnection. Options include FAULT, Coast Stop, Stop, and Continue LAST.
Answer: Answer: By setting the 'comm loss action' parameter to a value other than 0, such as Coast Stop or Continue LAST, you can potentially prevent faults that hinder local operation when the network connection is lost.
Answer: Answer: To ensure seamless switching to local operation when the network is disconnected, it is essential to properly configure the 'comm loss action' parameter and test the system thoroughly for network disconnection scenarios.
Answer: Answer: Common issues include encountering faults that disrupt local operation, indicating a need to adjust the 'comm loss action' parameter and conduct comprehensive testing for network disconnection scenarios.
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