4 Fault Isolation
4.3 Fault Isolation Concepts
314 HPM High-Performance Process Manager Service R688
Honeywell December 2020
I/O Link overruns
The use of AI PV scanning in the HPM improves the utilization of I/O Link resources. However, an
HPM can still encounter I/O Link overruns. Continuous I/O Link overruns will result in the generation of
an I/O Link overrun Soft failure.
In most cases, an I/O Link overrun indicates that the I/O Link Interface cannot handle the requested
amount of traffic. In order to alleviate the I/o Link overrun situation, changes must be made in to the
database to reduce or redistribute usage of the I/O Link for non-scan data during the offending cycle(s).
I/O Link overrun counters are maintained and displayed for each 1/4 second cycle on the Schedule
Information display.