Rockwell Automation FactoryTalk Historian SE 3.0 UniInt Interface User Guide - Manual (Page 39)

UniInt Interface User Manual 33
Windows Performance Counters
Counters are used to provide information as to how well an application, service, or driver is
performing. Developers can define counters for an interface. The total number of interface-
specific and UniInt counters cannot exceed 200. This maximum is hard coded. Any counters
in excess of 200 will be ignored.
Requirements
As of UniInt 3.5.0, UniInt always tries to enable Windows performance counters when the
interface runs as a service as long as the /disablecounters command-line parameter is
not specified. The following requirements must be met before counters will work.
1. The pictrdll.dll must be installed in the PIPC\bin directory in order for
performance counters to work.
2. The piperfmondll.dll is installed with PI API 1.3.4 and greater in the
PIPC\Interfaces\piperfmon_basic directory.
3. Counters are activated only if the interface is running as a Windows service. Counters
are not activated if the interface is running interactively.
Installing and Removing Interface Performance Counters
Interface performance counters are installed automatically by the interface the first time that
the interface is started as a Windows service. Since it is possible for other processes to
uninstall performance counters for the interface, the interface checks to see if performance
counters need to be re-installed every time that the interface is started as a service. Interface
performance counters are removed when the interface service is removed with the -remove
command-line option. The service can be removed even while the service is running.
However, once the service is removed, the performance counters cannot be viewed via the
Windows performance monitor unless the interface counters were already being viewed
before the service was removed.
Interface-specific performance counters are installed in the registry under
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\
<service_name>+<ServiceID>\Performance