Hardware reference guide

Ethernet Modules
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35013379 11/2011
Bandwith Monitoring
Bandwidth Monitoring allows you to monitor the NOE’s CPU allocation for each of
the following services: Global Data, I/O Scanning, and Messaging. The Bandwidth
Monitoring service retrieves workload data and returns one of two pieces of
information: whether the module has free resources or whether the module is
working at capacity. Knowing the resource allocation helps you:
z Decide about allocating your resources
z Determine the number of NOEs needed in a system
Available Services
The services accessed and monitored are:
z Global Data
z I/O Scanner
z Modbus Messaging
If you use Bandwidth Monitoring, you do not need to develop a new set of access
functions. The actual NOE CPU load is computed each second.
Bandwidth Monitoring Load Rates
The Bandwidth Monitoring service checks once a second and computes four (4)
values in private data:
z Percentage of NOE’s CPU allocated to Global Data
z Percentage of NOE’s CPU allocated to the I/O Scanner
z Percentage of NOE’s CPU allocated to Messaging
z Percentage of NOE’s CPU allocated to other services and idle
Results are returned as percentages. CPU time spent in other services is shown as
"Other" or "Free." Bandwidth Monitoring uses the same functions as used by SNMP.
The three service rates, Global Data, I/O Scanner, and Messaging, are computed
using the following formula:
(Current load * 100) / Maximum Load