Slow Response Time

Overview

The "Slow Response” diagnostic measures the time (in seconds) between a source device request and the corresponding acknowledgement from the destination device. E.g. A ReadProperty request to a device, and the devices request acknowledgement (which may contain the data requested, but does not have to).

Causes:

• The responding router is busy/overloaded
• There are too many hops (too many routers in between the requesting device and the responding device)
• The network is congested
• The destination controller is busy

Implications:

• Network Congestion: Heavy OT network traffic or congestion can lead to delays in transmitting and receiving BACnet messages, resulting in slower response times.
  
• Device Overload: If a BACnet device is handling a high volume of requests or tasks, it may not be able to respond promptly, causing delays in response time.
  
• Communication Errors: Intermittent communication errors or data collisions on the network can lead to delays in message delivery and response.
  
• Device Latency: Some devices may be prone to longer response times due to their processing capabilities or network positioning.
  
• Network Latency: Geographic distances between devices or the presence of multiple network segments can introduce latency in communication.
  
• Network Quality: Poor network quality, including low signal strength or unstable connections, can contribute to slow response times.
  
• Device Configuration: Incorrect device configurations, such as improper polling intervals or settings, might lead to slower response times.
  
• Device Health: Malfunctioning or deteriorating devices might not be able to respond as quickly as expected.
  
• Security Mechanisms: Complex security measures, like encryption and authentication, might introduce additional processing time, affecting response times.
  
• Network Troubles: Issues such as network loops, incorrect routing, or device collisions can lead to delays in message transmission.
  
  

How to fix it:

• Use OptigoVN Site Scope(s) to identify the path between the requesting and responding device for each slow response time (using your network drawing).
  
• Look at those routers in the BACnet browser and figure out what traffic is passing through them.
  
• Check the responding device, and see if the device is busy.