Victron ESS L2 Output Power Bug In Node-RED Integration

by StackCamp Team 56 views

This article addresses a critical bug encountered while using the Node-RED contrib-victron nodes to monitor the output power of a Victron Energy Storage System (ESS), specifically concerning the L2 phase. The issue manifests as a significant discrepancy between the power values reported by the Node-RED nodes for L2 and the values displayed on the Venus GX dashboard and confirmed by AC current clamp measurements. This article serves as a comprehensive guide, detailing the problem, its reproduction steps, supporting evidence, and potential implications for users relying on accurate power monitoring in their Victron ESS setups. We will delve into the specifics of the bug, offering insights and potential workarounds for users encountering this issue.

Understanding the Issue

The core of the problem lies in the inconsistent reporting of output power for the L2 phase within the Node-RED environment when integrated with a Victron ESS. Users have observed that while the L1 and L3 phases report power values consistent with the Venus GX dashboard and external measurements, the L2 phase consistently displays significantly lower values. This discrepancy raises concerns about the reliability of using Node-RED for accurate power monitoring and control in three-phase Victron systems. It is essential to accurately monitor each phase in a three-phase system to ensure balanced load distribution and prevent overloads. The observed bug undermines this capability, potentially leading to misinformed decisions and operational inefficiencies. Furthermore, the deviation in power readings can complicate tasks such as load balancing, grid interaction management, and overall system optimization.

Detailed Explanation of the L2 Output Power Bug

To provide a thorough understanding, let's dissect the issue further. The bug specifically affects the VE.Bus System Node's reporting of OutputPowerPhase2. In a properly functioning system, the power values reported by this node should align with the readings from the Venus GX dashboard, which is considered a reliable source of system data. However, in affected systems, the L2 phase consistently shows a lower power value in Node-RED compared to the Venus GX dashboard and actual power consumption as measured by AC current clamps. This discrepancy isn't a minor fluctuation; it's a substantial deviation that cannot be attributed to normal variations in power consumption or measurement inaccuracies. The impact of this bug extends beyond mere data inconsistency. It can affect critical control decisions based on power readings. For instance, if a system relies on Node-RED for load shedding or generator start-up based on power consumption thresholds, the inaccurate L2 reading can lead to incorrect actions, potentially causing system instability or failure. The inconsistent data also complicates troubleshooting and performance analysis, as users may struggle to reconcile the readings from different sources. Ultimately, the unreliability of the L2 power data undermines the confidence in using Node-RED for critical monitoring and control functions within a Victron ESS.

Reproducing the Bug: A Step-by-Step Guide

For those looking to verify the existence of this bug in their own systems or assist in troubleshooting, replicating the issue is straightforward. Here’s a step-by-step guide:

  1. Set up a three-phase Victron ESS with a MultiPlus inverter/charger connected to a VE.Bus system.
  2. Integrate the system with a Cerbo GX running Venus OS.
  3. Install the Node-RED contrib-victron nodes in a Node-RED instance.
  4. Create three VE.Bus System nodes in Node-RED, each configured to monitor the OutputPower for phases L1, L2, and L3 respectively.
  5. Deploy the Node-RED flow and observe the values reported by each node in the node status line or through debug messages.
  6. Compare the power values reported for each phase with the corresponding values displayed on the Venus GX dashboard. Also, use an AC current clamp to measure the actual current on each phase and calculate the power consumption.
  7. You should observe that the power value reported for L2 in Node-RED is significantly lower than the value displayed on the Venus GX dashboard and the power calculated from the AC current clamp measurements. The L1 and L3 values should be consistent across all three sources.

By following these steps, you can reliably reproduce the bug and confirm its presence in your setup. This replication is crucial for documenting the issue and providing concrete evidence for developers working on a fix.

Observed Behavior and Evidence

The core symptom of the bug is the underreporting of power on the L2 phase within Node-RED, compared to other measurement sources. Users have consistently observed that while L1 and L3 power readings align closely with the Venus GX dashboard and AC current clamp measurements, the L2 reading deviates significantly. This isn't a matter of slight discrepancies; the L2 power value in Node-RED is typically much lower, often by a substantial margin. The provided screenshot in the original bug report offers a clear illustration of this issue. In the example, L1 reports 442W, which matches the Venus GX dashboard and external measurements. Similarly, L3 reports 339W, again aligning with other sources. However, L2 shows a value of 263W in Node-RED, while the actual power consumption (as indicated by the Venus GX dashboard and presumably AC current clamps) is 556W. This represents a difference of nearly 300W, a significant deviation that cannot be ignored. These observations highlight that the issue is not random noise or minor fluctuations, but a systematic underreporting of power specifically on the L2 phase. This consistent pattern reinforces the likelihood of a bug within the Node-RED integration with the Victron system, rather than a hardware or configuration issue.

Impact and Implications of the Bug

The inaccurate power readings for the L2 phase have several potentially serious implications for users relying on Node-RED for system monitoring and control. First and foremost, it undermines the reliability of using Node-RED for accurate power monitoring. If the L2 power value is consistently underreported, users may make incorrect decisions based on faulty data. For instance, in systems designed for self-consumption optimization, the inaccurate L2 reading could lead to suboptimal energy usage and increased grid reliance. Secondly, the bug can affect load balancing in three-phase systems. If the system relies on Node-RED for load shedding or generator start-up based on power consumption thresholds, the incorrect L2 reading could trigger inappropriate actions, potentially causing system instability or failure. For example, if Node-RED believes the load on L2 is significantly lower than it actually is, it might not shed load when necessary, leading to an overload on that phase. Thirdly, the inconsistent data complicates troubleshooting and performance analysis. When power readings from different sources (Node-RED vs. Venus GX) do not align, users may struggle to identify the true state of the system and diagnose potential issues. This can result in wasted time and effort in resolving problems. Finally, the overall confidence in using Node-RED for critical monitoring and control functions within a Victron ESS is diminished by this bug. Users may be hesitant to rely on Node-RED for essential tasks if the data it provides is questionable. In summary, the L2 power reporting bug in Node-RED has significant consequences for system accuracy, reliability, and user confidence.

Potential Causes and Workarounds

While a definitive root cause analysis requires investigation by the developers of the Node-RED contrib-victron nodes, some potential causes can be hypothesized. One possibility is a data type mismatch or incorrect unit conversion within the Node-RED node's processing of the L2 power data. It's conceivable that the node is misinterpreting the raw data received from the Victron system for the L2 phase specifically. Another potential cause could be an issue with the Modbus register mapping or data addressing within the Node-RED node's communication with the Victron system. If the node is attempting to read the L2 power data from an incorrect register or memory location, it would obviously result in inaccurate readings. A third possibility is a bug in the node's internal logic or calculations for the L2 phase power value. It's possible that a specific calculation or data transformation is being applied incorrectly to the L2 data, leading to the observed underreporting. While the exact cause remains to be determined, some temporary workarounds might mitigate the issue. One potential workaround is to use a scaling factor or offset within Node-RED to adjust the L2 power value based on the discrepancy observed. By comparing the Node-RED L2 reading with the Venus GX dashboard value, users can calculate a correction factor and apply it within Node-RED to obtain a more accurate reading. However, this is a manual and potentially error-prone workaround, and it's not a substitute for a proper fix. Another workaround, if feasible, is to rely on the Venus GX Modbus TCP registers directly for L2 power data, bypassing the Node-RED contrib-victron nodes altogether. This would require a custom Modbus implementation within Node-RED, but it could provide a more reliable data source until the bug is fixed. Ultimately, the best solution is for the developers of the Node-RED contrib-victron nodes to investigate and resolve the bug in a future release.

Version Information and System Configuration

Understanding the environment in which this bug occurs is crucial for developers to replicate and resolve it effectively. The original bug report provides valuable version information. The system experiencing the issue consists of a Cerbo GX running Venus OS version 3.54. This is a key component in the Victron ESS, acting as the central communication and control hub. The Node-RED instance is running version 3.1.10, which is a relatively recent version of Node-RED. The specific version of the Node-RED contrib-victron nodes is not explicitly mentioned in the original report, but this information would be highly valuable for further investigation. Knowing the exact version of the nodes would allow developers to pinpoint the code base where the bug might reside. In addition to the software versions, the system configuration is also relevant. The bug report mentions a three-phase system, which means the inverter/charger setup and wiring configuration are likely more complex than a single-phase system. The loads are connected to OUT1 only, which may or may not be a factor in the bug, but it's an important detail to consider. Any other relevant system configuration details, such as the specific MultiPlus model, battery capacity, grid connection settings, and any other installed Victron components, could potentially shed light on the issue. Providing a complete picture of the system environment is essential for successful bug resolution.

Conclusion and Call to Action

In conclusion, the L2 output power bug in the Node-RED contrib-victron nodes poses a significant challenge for users relying on accurate power monitoring within their Victron ESS. The discrepancy between the Node-RED readings and the Venus GX dashboard, as well as external measurements, undermines the reliability of using Node-RED for critical control and decision-making processes. The bug has potential implications for system optimization, load balancing, troubleshooting, and overall user confidence. While some temporary workarounds may mitigate the issue, a definitive solution requires investigation and resolution by the developers of the Node-RED contrib-victron nodes. We urge the developers to prioritize this bug and release a fix in a future version of the nodes. In the meantime, we encourage users experiencing this issue to document their observations, share their experiences in relevant forums, and provide feedback to the developers. The more information that is gathered and shared, the faster a solution can be found. We also encourage users to explore and share any potential workarounds they discover. By working together, the Victron community can help ensure the accuracy and reliability of Node-RED integration with Victron ESS systems. If you are experiencing this bug, please provide detailed information about your system configuration, including software versions, hardware models, and specific observations. This information will be invaluable in helping to diagnose and resolve the issue.