Correcting Bus overload problems - Metasys - LIT-12011034 - General System Information - Metasys System - Release 11.0

MS/TP Communications Bus Technical Bulletin

Product name
Metasys System
Document type
Technical Bulletin
Document number
Release 11.0
Revision date

Excessive data communication on the MS/TP bus can degrade system performance. To reduce the load on the bus, consider the following:

  • Unmap points you do not need.

  • Minimize the number of COVs on the bus; see Counting the COVs.

    • Check and increase the COV increment for noncritical points.

    • Use a timed COV interval for fast changing points. Set the Use COV Min Send Time attribute to True.

    • Lengthen the COV timed interval COV Min Send Time 10-255 in the device object. The default is 15 seconds.

  • Check for and correct unstable sensors.

  • Reduce the number of devices on the bus, if possible.

  • If running at less than 38.4k baud, increase the baud rate (if possible).

  • Verify repeaters, if applicable.

    • Verify that repeaters are used where needed.

    • Verify that repeaters are configured and wired correctly.

    • Verify that BACnet Routers are associated with a single integration (Remote Field Bus) at a single supervisory device.