OptigoVN Diagnostics Reference Table

Diagnostic	What It Means	Why It Matters	Common Causes	How to Fix
BACnet Request Retry	A device is resending a request due to missing or delayed acknowledgment.	Indicates communication delays or failures between devices.	Network congestion, slow/unresponsive devices, incorrect APDU timeout settings.	Check network traffic levels Verify device responsiveness Adjust APDU timeout settings
Busy Router Backpressure	A router is overloaded and cannot process incoming traffic.	Can cause latency, dropped packets, and degraded network performance.	Excessive traffic, undersized routers, poor network design.	Reduce broadcast traffic Segment the network Upgrade or reconfigure routers
Detected Circular Networks	Packets are looping repeatedly through the network.	Creates excessive traffic and instability.	Improper routing, network loops, misconfigured topology.	Identify loop paths Correct routing configuration Remove redundant connections
Device Global Discovery	Multiple global Who-Is requests detected.	Floods the network with broadcast traffic (I-Am responses).	Misconfiguration, address conflicts, faulty devices.	Limit Who-Is scope Fix duplicate addressing Investigate noisy devices
Duplicate BBMD	Multiple BBMDs forwarding the same broadcasts.	Multiplies broadcast traffic and can overwhelm the network.	Multiple vendors configuring BBMDs independently.	Ensure only one BBMD per subnet Align BBMD strategy across vendors
Duplicate Device Address	Two devices share the same network address.	Causes communication conflicts and instability.	Manual addressing errors.	Assign unique addresses Audit device configurations
Duplicate Device Instance	Two devices share the same BACnet instance number.	Breaks device identification and communication.	Configuration mistakes during setup.	Assign unique instance numbers Follow BACnet addressing best practices
Duplicate Network Number	Multiple routers use the same network number.	Leads to routing conflicts and misdirected traffic.	Improper router configuration.	Ensure unique network numbers Review router configurations
Error Messages – Interoperability	Devices cannot properly communicate due to compatibility issues.	Leads to failed communication between vendors/devices.	Unsupported features, vendor-specific implementations, profile mismatches.	Verify device compatibility Align supported BACnet services Update firmware if needed
Error Messages – Operational	General system or device faults.	Indicates broader system health issues.	Device failures, network instability, configuration errors.	Review related diagnostics Check device health Investigate alarms and logs
Error Messages – Programming	Errors in logic, configuration, or control sequences.	Can cause incorrect system behavior.	Programming mistakes, mapping errors, bad configurations.	Review control logic Validate mappings and sequences Correct configuration issues
Error Messages of Unknown Type	The message does not fit a specific error category.	Still indicates something abnormal is happening, even if classification is unclear.	Undetermined system behavior, ambiguous faults, data corruption, unexpected results, unrecognized events.	Correlate with other diagnostics look for patterns Review capture context to narrow the cause.
Excessive BACnet Discovery	Specific BACnet objects are being repeatedly queried using WHO-HAS.	Repeated discovery traffic can degrade performance and often points to stale or bad references.	Programming errors, deleted/unreachable objects, outdated object-name references.	Find the source of repeated WHO-HAS traffic  Correct outdated or misconfigured object references.
Excessive Change of Value (COV) Rate	COV messages are occurring too frequently.	High message rates consume bandwidth and reduce system stability.	Noisy devices, overly sensitive reporting thresholds, programming/configuration issues.	Review COV configuration, thresholds, and device behavior Reduce unnecessary reporting.
Excessive Max Master	The MS/TP max_master value is set higher than needed.	Causes unnecessary poll-for-master traffic and slows communications.	Factory default value left unchanged.	Set max_master closer to the actual highest master address on the segment.
Excessive MSTP Round Trip Token Time	The average MS/TP token trip time is longer than expected.	High latency can lead to conflicts, delays, and lost messages.	Often wiring-related issues.	Inspect MS/TP wiring quality, topology, terminations, and device loading.
Excessive Number of Devices on Single MSTP Network	More than 32 master devices were detected on one MS/TP network.	Too many devices on one segment usually reduces speed and integrity.	Overloaded segment design.	Split the network into smaller segments and reduce master count per trunk.
Excessive Read Rate	Read requests are happening too frequently.	Can increase response times, consume resources, and destabilize the network.	Aggressive polling, inefficient programming, unnecessary reads.	Reduce polling frequency   Tune read rates to actual operational needs.
Excessive Token Hold Time	An MS/TP device is holding the token longer than 500 ms.	Leads to congestion and delayed messages.	Device trying to send too many messages before passing the token.	Reduce device traffic and review programming or workload on the offending device.
Excessive Traffic Rate: Broadcast by Source	Broadcast packet frequency exceeds the test threshold.	Broadcast floods affect every device and can seriously hurt performance and stability.	Frequent discovery, noisy programming, excessive alarms/notifications, poor broadcast control.	Identify the top broadcast sources Reduce broadcast frequency  Use routing strategy where appropriate.
Excessive TrendLog Buffer Read Rate	TrendLog buffer read requests are occurring more than once every 10 minutes.	Generates unnecessary traffic and may indicate bad programming or configuration.	Over-aggressive trending reads, polling logic issues.	Reduce read frequency and review TrendLog access logic.
Excessive TrendLog Buffer Ready Notification	A TrendLog buffer is filling more than once every 10 minutes.	Can indicate excessive logging volume and added traffic load.	Configuration or programming issues, overly frequent logging.	Review TrendLog intervals, trigger logic, and notification setup.
Number of TrendLog Objects	Informational result showing which devices currently have TrendLogs active.	Useful for visibility into logging load and storage usage.	Normal system configuration.	Remove unnecessary TrendLog objects to reduce memory and storage usage.
Excessive Write Rate	The BAS is writing to a device unusually often.	High write frequency increases traffic and may shorten device life.	Incorrect settings, inefficient control programming, frequent control-loop adjustments, excessive logging.	Review write logic, tune control loops, and reduce unnecessary writes.
Gap in MSTP Device Addressing	MS/TP device addresses are not sequential.	Missing address gaps cause repeated poll-for-master delays.	Non-sequential addressing on the MS/TP trunk.	Reassign addresses to reduce unnecessary gaps where practical.
Lost Tokens	A Reply-To-Poll-For-Master message suggests token problems on the MS/TP network.	Can cause communication loss and dropped packets.	Usually a physical wiring issue, though it can also appear while adding a device during capture.	Inspect MS/TP wiring, polarity, grounding, shielding, and recent device changes.
Checksum Errors	Packets are corrupted (garbled) and dropped.	Indicates physical layer issues affecting data integrity.	Wiring faults, electrical interference, failing hardware.	Inspect cabling and terminations Check for interference Replace faulty hardware
Fully Unreachable Devices	One or more devices never responded to Who-Is with I-Am during the capture.	Indicates devices that are completely unavailable.	Power failure, physical disconnect, device failure, configuration problems, firewall/security settings.	Check power, connectivity, addressing, and any routing or security barriers.
Partially Unreachable Devices	One or more devices responded inconsistently to discovery during the capture.	Indicates intermittent availability rather than full outage.	Congestion, geographic latency, power fluctuations, software issues, device overload.	Check response consistency, network load, power quality, and device health.
Router Rejecting Network Messages	A router is not forwarding some messages or communication requests.	Can result in data loss, breakdowns in communication, and instability.	Misconfigured policies, overload, congestion, security settings.	Review router configuration, traffic load, and any message filtering or security policies.
Slow Response Time	A device took longer than recommended to respond to Who-Is with I-Am.	Can delay monitoring and reduce responsiveness of critical systems.	Congestion, overloaded responding device, too many network hops, latency.	Review path length, device load, and network traffic  Reduce bottlenecks.
Unacknowledged Requests	A device sent a message but did not receive an acknowledgment.	Can lead to data loss, delayed fault detection, and degraded performance.	Destination device offline or busy, router issues.	Check destination device availability, router path health, and device load.