Excessive Write Rate

Overview:

The "Excessive Write Rate" diagnostic fails when a building automation system is performing write operations (updating data or settings) to a device or sensor at an unusually high frequency. Excessive writes can have negative impacts on the system's performance, device longevity, and overall stability.

Causes:

• Misconfiguration: Incorrectly configured settings may unintentionally lead to frequent or unnecessary write operations.
  
• Faulty Programming: Malfunctioning or inefficient control programming can inadvertently trigger excessive write operations.
  
• Control Loop Instabilities: Rapid and frequent adjustments to control loops can lead to excessive write operations, affecting device outputs.
  
• Data Logging: If data logging is performed excessively, it can lead to unnecessary updates and writes to storage.
  
• Network Load: Excessive write operations can generate high levels of network traffic, impacting network performance.
  
• Device Wear: Continuous write operations to devices, especially in scenarios like setpoint changes, can contribute to increased wear and reduced device lifespan.

How to fix it:

• Use OptigoVN Site Scope(s) to identify the addresses of all devices with excessive write rates. Refer to our BACnet Object glossary to identify the points being written excessively.
  
• Configuration Review: Review and verify configuration settings for write operations to ensure they are appropriate for the system's operational needs.
  
• Write Frequency Guidelines: Set write frequencies based on the frequency of control changes, data logging requirements, and system performance goals.
  
• Optimization: Optimize control logic to avoid unnecessary or rapid write operations, especially for parameters that don't require frequent updates.
  
• Control Loop Tuning: Tune control loops to prevent rapid and unnecessary adjustments that lead to excessive write operations.
• Data Logging Strategies: Implement efficient data logging strategies to minimize unnecessary write operations for logging purposes.
  
• Rate Limiting: Implement rate-limiting mechanisms to prevent overly frequent write requests.
  
• Network Monitoring: Monitor network traffic and resource usage to detect patterns of excessive write rates.
  
• Testing: Conduct testing to ensure that the system's write rates align with operational requirements and do not negatively impact device performance.