BACnet Buffer Overflow
Buffer overflow occurs when a device’s receive buffer fills before it can process incoming frames. Extra APDUs are dropped, causing timeouts and retries. Common on busy MS/TP trunks or with resource-limited devices.
Common Causes
- Excessive polling or COV subscriptions targeting the same device
- Device CPU or memory too slow for traffic load
- Large ReadPropertyMultiple or segmented responses backing up
- Too many clients querying a single device simultaneously
Fix Steps
- Reduce polling intervals for the affected device; stagger scans if possible.
- Limit COV subscriptions; use change-of-value instead of frequent reads where practical.
- Upgrade device firmware for improved buffer handling; check release notes.
- Spread client requests across time; avoid burst traffic to one device.
- Consider a more capable controller if load cannot be reduced.