Performance considerations for third-party BACnet devices - Metasys - LIT-1201531 - System Integration - BACnet Controller Integration - 11.0

BACnet Controller Integration Technical Bulletin

Brand
Metasys
Product name
BACnet Controller Integration
Document type
Technical Bulletin
Document number
LIT-1201531
Version
11.0
Revision date
2022-02-09
Language
English

Network performance can degrade when you add third-party devices on the same IP network or MS/TP trunk if those devices do not meet the Required recommendations in Table 1. Actual job experience has shown as few as five devices can create significant performance issues; although other variables can affect performance, such as the number of objects per device. To improve network performance, we recommend that third-party devices also meet the Highly Desired recommendations in Table 1.

Table 1. Third-Party BACnet Device Performance Recommendations

MS/TP Trunk, IP Network, and BACnet Services

Recommendation

Devices On MS/TP Trunk

MS/TP Master Device

Required

At least 38,400 bps

Highly Desired

Application Layer Protocol Data Unit (APDU) size 480 bytes

Desired

APDU size >200

Highly Desired

Segmentation on MS/TP

Desired

Devices On IP Network

Segmentation on IP devices

Highly Desired

Minimum APDU size 1024

Highly Desired

BACnet Services

Conform at a minimum to BACnet Version 1 Revision 4 specification

Protocol revision 15 or higher is desired.

Device supports a minimum of a B-SA profile or a B-SS profile.

Required

BACnet listed or Certified

Highly Desired

+ Read Property Multiple, Execute

Highly Desired

+ Subscribe COV, Execute

Highly Desired

+ Write Property Multiple, Execute

Highly Desired